Oh look, it's an old friend: a stone tablet with an emerald inset on top. It's inscribed with an alternating sequence of + and - signs, and an ellipsis that would make your math teacher gasp in fear. On the wall above and to the left, there's a picture frame with 5 rings and a row of numbers separated by circles, but the numbers are mirrored and the frame is screwed down. On the right, there's a four-digit safe which, as you're used to by now, opens a panel in the wall beneath its lock.

Turn left to find a pipe that seems like it would drain into a hole in the ground, were it not missing some parts on its junction and end. A pair of lights next to the pipe are off and green, respectively. To the left, a hole in the wall has a downward pointing arrow inviting you to look down, which you do to find something rectangular at the very bottom, way beyond what your puny Reacher can handle.

Turn left to find the doorway back, and also a black-and-white grid safe with loads of colored markings along the top and left. The five squares along one diagonal of the grid are missing, and an OK button is in place of one of them in the lower-right.

Turn left to find another grid of buttons on the wall, where the buttons are marked with plus and minus signs and are connected vertically, horizontally and diagonally. An emerald is inset in the panel next to the reset button, and the safe seems to open a trapdoor on the ground. There's also a clock here that seems to have stopped.

Use the clue from the tablet to unlock the grid of plus and minus buttons.

You have to click a plus button, followed by an adjacent minus button, followed by an adjacent plus button and so on until all sixteen buttons have been pressed.

Hint: If you assume the path forms a Hamiltonian cycle, you can immediately deduce a large part of it.

Start the path as follows:
+987
--56
+-14
+-23
and then you have some choices to finish the path as long as you hit the remaining plus buttons from top to bottom.

When you're done, all the buttons spin really fast and the trapdoor opens up and there's a piece of cloth and a clue with digits separated by circles, but one number seems missing. There's also something new: a series of colored lines.

Look back at the button grid to find some colored lines highlighted along a diagonal. That's still not enough information to do the math, so it's time to do something else.

Use the screwdriver to unscrew the picture frame, leaving the five rings on the wall, covered with an oil stain.

Placing the picture frame in the trapdoor's space, you find that the circles align, but the resulting clue is unreadable.

So pick it up again, flip it over, and put it down. Now the digits match perfectly to form five two-digit numbers.

The lines between the circles are pink, yellow and cyan, and the similar-colored lines run from the lower-left to upper-right of its diagonal grid.

The buttons on that diagonal have rotated to read + ∕ × +, but the math doesn't work out if you use those symbols.

Instead, you need to rotate your view until the diagonal line is horizontal. The symbols then become ×−+×.

Placing those symbols in the circles, the formula evaluates to 2668-91+2160=4737.

Enter 4737 in the four-digit safe, and open it to get a small turning key. According to the text description, this key fits on a faucet to open up a water valve.

So use the faucet key on the faucet, and turn it so that water pours into the hole.

Wet the cloth in the water stream, and use it to wipe up the five-ring picture. Something looks very slightly different about it.

Use the clue from the five rings to unlock the other grid safe.

(There are no other clues for this puzzle, so I'll give you a hint: your final code should be symmetric.)

Whenever two rings are linked, click both buttons where their rows and columns intersect to turn them white.

There are a total of 6 such links: green-blue-yellow-green-black-yellow-red. Thus your grid should look like this:
- R B Y G K
R - b W b b
B b - W W b
Y W W - W W
G b W W - W
K b b W W -

Click those 12 (W) buttons to turn them white, and then the OK button.

The safe opens so you can take a round handle with a square protrusion.

Use the handle on the pipe junction, and turn it to pump the water out.

A box floats up the hole in the wall, and then a beep informs you that you're out of water.

The box has a screwed-on lid, so unscrew it to find a shiny gray key.

So you leave the room holding a key and the box it came in.

Go back to the main room and insert the key in the matching door lock to open up the next room.

It's another stone tablet! This one has a gray gem (whatever that is), and a green square around a yellow circle with black in between, and a clue below about 18 yellow circles. To the right of it is a complicated-looking ball machine with a 1/100000 chance of success. On the left, there's a club suit mark in pink, and a lever that tilts the ball machine briefly before springing back.

Turn left to find a bunch of things on a wall: a pink heart mark, a grid of blue lamps with the upper-left one lit green, a safe with four pink buttons and a clockwise arrow, and a bucket trapped behind glass with numerals marked on it. (You'd think the hammer would instantly solve this problem, but it's not that smashy.)

Turn left to find the doorway back, which has a stopped clock and a pink diamond on the right side. On the left is a safe which has a red hole in its upper right and a downward arrow starting at an unlit lamp and passing through two buttons.

Turn left to find a set of three safes in different shapes, with buttons that extend green lines across their surfaces. The middle safe is marked with a gem. There's also a pink spade mark at the wall corner.

Use the clue from the stone tablet to unlock the middle (diamond) panel on the spade wall.

(Experiment with it a bit.)

Yellow circles appear on the panel whenever a small square is formed by the green lines. You need to form exactly 18 of these small squares.

(Hint: all but two of the lines should be fully extended.)

Click every button twice except for the leftmost one on the upper-left side and the rightmost one on the upper-right side. Click the former just once.

Then press the OK button, and its panel opens up to let you have a green ball with a letter and number separated by a line.

The middle panel now shows a cyan square followed by ×13.

So use the clue from the middle panel to solve the left panel, which works pretty much the same way.

Click every button twice except for the middle ones on the top and right side. Click the former just once.
Then press the OK button to open the safe and get an orange ball with no markings.

The left panel now displays a red triangle followed by ×19.

Use the clue from the left panel to solve the right panel, which works pretty much the same way.

Click every button twice except for the top ones on the left and top-left sides. Click the former just once.

Then press the OK button to open the safe and get a gray panel labeled 2.

The right panel now displays a bunch of pink card suits.

Use the suit clues to unlock the four-button panel above the bucket.

In the order indicated by the arrow on the panel, the suits are ♣♠♥♦♥ ♣♠♠♦♥.

But the club, spade, heart, diamond suits are on the lower-left, upper-right, upper-left, lower-right corners of their respective sides.

So push the ⌞⌝ ⌜⌟ ⌜⌞⌝⌝⌟ ⌜buttons on the panel, and the glass raises so you can get the empty bucket.

You're not tall enough to do anything with the lamp puzzle, unless you use your Reacher.

So use the clue from the bucket to solve the lamp puzzle.

Hint: there's another odd one out.

The green ball suggests that you should convert the numeral Ⅲ to 3.

The numbers 6 and 3 are coordinates, so you need to touch the lamp on the sixth row (from top) and third column (from left).

So poke it with the (extended) pointer, and the panel opens up to reveal orange and green holes over a locked metal cover.

Place both balls in the matching holes (they're too large for any other holes), and the machine gives you access to a blue ball.

You need to weigh down the lever on the wall, but you don't have things heavy enough to fill the bucket with.

So go back to the previous room and fill the bucket with the water there (since the pipe is dry, you'll need to use the bucket on the wall hole).

The full bucket is sufficient to weigh the lever down, and now the ball machine displays a much better 1/1 probability.

So place the blue ball in the machine, and it rolls around a few times before dropping into the front hole.

So check the tray beneath the machine to find a red ball!

Place the red ball in the matching hole (next to the door), and the lamp and buttons on that panel light up.

That green lamp looks a little familiar.

Look at the grid of blue lamps again. This time, it displays a black arrow and some red dots.

So use that clue to unlock the panel.

Rotating the arrow to point down, you find that the red dots are on the RRLLLLRL sides of the arrow.

Then press the OK button, and the safe opens... or at least it tries for a while, and then gives up with a resigned beep. You can just see a key through the narrow gap.

Well, it had to happen sooner or later, with no maintenance workers this far into the ruins. I guess you're just stuck here now... unless you have a trick up your sleeve?

Use the pointer to drag the brown key towards you, and now you're ready to move on to the next room!

The tablet in this room has two gems, red and yellow. In between, there's a clue about slanted and horizontal platforms and an arrow pointing to a reddish rectangle. Above the tablet and to the right, there's a lever that you somehow don't have the strength to move. On the left, a four-digit safe has a different color for each digit.

Turn left to find a six-button safe with a brick-like pattern, a weird black-and-white marking, and what appears to be an unlit lamp, but the buttons on the safe don't work. To the left of it, a pulley is hidden behind glass that's resting on an orange panel labeled ?. There's a stopped clock at the upper-right and an X mark just below the safe.

Turn left to find the doorway back. On the right, the pulley ends in a raised shutter and a tiny yellow panel labeled ? is sitting there. On the left, a yellow gem marks a clue about scales carrying golden weights.

Turn left to find a monstrosity of a machine. A giant empty column on the right passes beside a green button that moves a hook back and forth and a purple button that opens a shutter, and ends in a drain that's probably the same drain under the larger grate on the floor which has a water indicator and a blue button next to an unlit lamp. The hook is attached to a pulley, and the other end of the pulley appears to connect to a weight that's blocking a toy car. (But the green button doesn't move it.) The car sits on a ramp, and three other ramps sit above mathy puzzle panels with trapezoidal holes, leading to a small opening where a blue panel labeled ? rests. Finally, there's a red panel with a red gem and an Open button, but of course it doesn't open.

You should now have four colored panels, so use the clue from the colored panels to unlock the four-digit safe.

Colorblind help

Each panel should represent a digit (whether or not it has a question mark).

Use the ramps like weighing scales to deduce the digits for each panel, starting with the digits that are already marked.

You can get the middle scale to balance in three ways:

Pink (5) = Gray (2) + Orange, so Orange = 3.
Pink (5) + Gray (2) = Blue (7), so Blue = 7.
Pink (5)+ Orange (3) = Blue (7) + Yellow, so Yellow = 1.

Now that you know the values of the panels in your inventory, you can use them to find the red (and green) values:

Red = Orange (3) + Yellow (1), so Red = 4.
Blue (7) + Yellow (1) = Green, so Green = 8.

Putting all this together, Orange Yellow Blue Red = 3174.

So enter that in the four-digit safe to open it and get a cyan panel labeled 6.

Use the clue from the tablet to set the ramps correctly.

Hint: you have just enough weights to do it.

You need to outweigh Red (4), so place the Orange (3) and Gray (2) panels on its right.
Next, you need to outweigh Pink (5), so place the Cyan (6) panel on its right.
Next, you need to balance Green (8), so place the Blue (7) and Yellow (1) panels on its left.

Then press the Open button on the safe marked with a ruby, and it opens up so you can get a weight with a handle. It's marked 20, but it doesn't feel that heavy.

Perhaps you could open up the drain cover if you just had a bit more water.

Go back to the previous (gray) room and pick up the bucket there.

Then empty it into the open grate, filling up the water meter.

Now you can press the blue button to fill the column with water (or drain it) while the glass door is closed.

You need to attach the 20 weight to the hook in the machine, but how do you get it up there? It certainly doesn't float on water.

Stack it on top of the wooden box you're still holding. (Do this in your inventory.)

Then (open the glass door and) use it on the base of the column, where it fits perfectly.

Then push the blue button to pump the water up, and then the green button to move the hook, and then the blue button to release the water.

The 10 weight rises, the car races off to the left, bounces against the wall back along the ramps to the right, and comes to another bouncy stop. So you pick up the car and open it... all that for a simple note with a heart and a cross.

It's a pink heart, so that means you have to go back to the gray room again.

Face the heart wall, and click the spot exactly where the X was in the brown room. (At the center of the wall, to the right of the glass where you got the bucket.)

Now zoomed in on the blank wall, smash it with your hammer...

...you can't, because it's soft! It feels just like a thin layer of fabric.

So use your cutter instead. You cut up the wall, and tear the wallpaper away to find a cute face formed by a button under two unlit lamps.

So push the button, and the face turns green. Don't get too excited, you're not summoning anything yet.

Go back to the brown room, where something's now glowing green.

It's the lever on the wall behind the stone tablet! So pull it, and the tablet extends out of the ground to reveal a grid of uncomplicated symbols. (Which places the grid right under the yellow gem.)

There were two lamps above that button, so look for another thing that glows green.

The six-button safe under the clock is now activated, and you can push its buttons to change up the black-and-white patterns.

Use the clues marked with topaz stones to unlock the six-button safe.

Following the gold picture, you need to take the 2nd, 1st, 6th, 5th, 2th, 2nd symbols from each column.

So copy those symbols by clicking the buttons 3, 2, 10, 12, 7, 7 times. (The 4th and 8th presses on each button change the symbol rather than rotating it.)

Then press the OPEN button to slide the panel down. Behind it, there's a single yellow rope.

So cut the rope, and you hear a loud boom. The other end of the rope has slid over the pulleys and released the shutter to the left.

The closed shutter panel has an amidakuji machine with 6 columns, and some of the bars are colored and controlled by the side buttons. (If you're not familiar with this, press the Start button to see how it works.)

With a total of 256 combinations (which can be reduced to 128 with advanced techniques), you could be here for a really long time.

What you need is a clue. Did you miss one?

Looking back at the brick-patterned safe, you find that its panel didn't slide down very far, and part of the X mark is still visible, right under the triangle symbol. Doesn't that look a bit like something else?

It's an A. Each of the other symbols looks like a letter, and the letters for each symbol form the clue CUTALL.

So "cut all" the bridges on the amidakuji machine by clicking every button.

Then click Start again, and watch the shapes dance to the music and land in their matching holes. When that's over, the picture to the left of the door rises up to reveal a packet containing a key!

So use your trusty Cutter to extract the yellow key, and you're all ready to move to the next room.

The stone tablet (with another yellow gem) has a very confusing diagram with red squares, white rectangles and black triangles. To the right of it is a safe with somewhat happy faces, but the buttons are fake and it's just a picture. On the left, a four-digit safe has horrendously misaligned buttons that make loud clanging noises.

Turn left to find a closed green window at the top of the ceiling, a daruma-otoshi machine with an unusual setup, and a bunch of nails in the wall holding up a gray figurine. The nails seem a bit crooked too.

Turn left to the doorway back with a weird protrusion over it. On the right, there's a stopped clock on the wall over a cracked glass panel that covers a familiar-looking key in a stand. On the left, there's a safe with a big arrow pointing at an OK button (which doesn't work).

Turn left to find a green statue with folded arms, and instead of a face there's just three holes arranged vertically. His upper half sits on a platform with an up arrow button. Around him are four rectangular holes with platforms at their bases, and the holes and platforms come in four different sizes.

Use your trusty hammer to smash the glass case, and an alarm triggers and rusty iron bars lock you in.

You got access to the pink key, but now you don't have access to the door!

On the bright side, the big arrow safe is now activated, and seven new buttons appear.

Use the clue from the door bars to unlock the arrow panel.

The tapered body of the arrow indicates that you should arrange the bars in order starting with those having the widest (unrusted) middle.

That order is 6342715, so click the 6th, 3rd, ... , 1st, 5th button from the left to raise the bars.

Before you move to the next room, there's another puzzle you can solve here.

Solve the daruma-otoshi puzzle using the clue on the stone tablet.

Each block of the puzzle can only be hit from the right. The tablet says that the big block can only be hit if it's unblocked on the left and has an exposed surface on the right, and if it rests on the gold platform you win!

The blocks do have a tendency to defy physics, which makes this bost easier and harder.

The blocks, from top to bottom, are Red, Blue, Yellow, Green (lime), Purple/Pink (magenta), and the buttons are in the same order from left to right.

So press the blocks in the following order:
RBYGP RBYG RBY
followed by
Y G RBG
to form a stack: red, blue, green, yellow. With purple left behind, you can continue pushing the stack:
RBGY RBGY RBG RB
and finish off by pushing the head to the end:
R R R.

The window opens and a tiny button falls to the floor. It looks like an open button for an elevator, but we don't have one here.

The stone tablet here has a pink gem and a clue with arrows pointing in and out of several crystals. At the upper-left, a creepy mask on a shelf has a hexagonal hole on its forehead and three buttons for a nose, and you can turn it over by clicking its right edge to find three more holes on the back. On the right side, there's a safe with footprint buttons on a striped background with an upward-pointing right arrow (as well as the panel that the safe opens).

Turn left to find a dark glass panel with two round buttons that don't work, and a rectangular hole in the ceiling above it. To the left, a machine with a hexagonal keyhole spits out the corner of a blue piece of paper, but the rest of it seems to be stuck inside. On the right, there's a safe with five buttons arranged around a central OK button, as well as a familiar marking at its top right.

Turn left again to find the doorway back with a stopped clock above it. On each side of the doorway are weird paintings with weird people around weird pyramids doing weird things with light. The thing that most interests you, of course, is the key in the hand on the guy in the right painting. Snap out of it, it's not real! What's real is the second pyramid from the left, which turns out to be a triangular wooden block.

Turn left again to find a familiar setup: a closed round window near the ceiling and a rectangular hole near the floor. On the left is a machine with a grid of square enclosures with crystals controlled by buttons on the top and left. The middle crystal rotates in time to a row of lights on the right side that flash one at a time. On the right of the screen, there's a note with a grid of numbered colored circles.

Use the clue from the pink gem tablet to unlock the crystal machine.

From the rules shown on the tablet, you can deduce that the crystals have to be placed as follows:
/\/
|||
|\/
So set up the top row by clicking the left and right buttons along the top once each, then the other rows by clicking the middle and bottom buttons once and thrice.

Then wait for the correct timing to release the really slow light beam.

The correct timing is precisely when the lit bulb on the right changes from the 2nd to the 3rd.

When you have it correct, the light beam lands in the hole at the lower left, and the window near the ceiling opens up. No button drops this time.

Speaking of button drops, you still have the button from the other room, so place it in the rectangular hole near the floor.

Say, that's an unusual position for an elevator button. Wonder what this opens?

It opens a trapdoor to the basement, this time without a cushion at the bottom.

Just to rub it in, the first thing you see upon getting up is a ladder right beside the hole. A button panel on the left reminds you of elevator panels again, but this one goes up, down and... left? The left button is lit.

Turn left to find another such panel with neither its left nor right button lit. Below it, a big red X marks a rectangular mousehole through which you can vaguely see some sort of handle. There's also a digital clock which is turned off.

Turn left to find another such panel with up, down and left buttons, all unlit. There's also a track along the floor-wall corner, with some painted footprints climbing up the wall.

Turn left to find a row of light bulbs over a glass porthole which is flooded with light from the other side.

Turn on your flashlight and use it on the mousehole to retrieve the handle from inside.

As you back out, the hole returns to its former darkness.

Press the lit left-arrow button, and the ladder slides to the left... past the hole that you need to climb.

All you can do is press the down button- oh no, that retracts the whole ladder!

All is not lost. You can still turn left and press the left button. The X turns into a red arrow indicating the direction of the rumbling.

Turn left and press the up button, and the ladder reappears from the ground right in front of the footprint tracks.

Some of the footprints are now covered, but others seem to form a clue that you should note down for later.

Send the ladder left, then down, then back across the room, then up to the hole.

Climb the ladder out of the hole, and then use the footprint clue to unlock the footprint safe in the pink room.

From bottom to top, the (non-covered) footprints appear on the RLRLLRRL sides of the ladder.

So click those footprint buttons, and the safe opens to let you take a figurine that's larger than the previous.

Use the handle you picked up downstairs on the paper machine, and it "prints" out a paper strip with a sequence of moon phases... but some of the moons shown are physically impossible.

Use the clue from the paper strip to unlock the glass porthole downstairs.

(The game description mentions a bug in which the last light won't turn off if all the others are off. If you encounter it, the workaround is to turn them off in a different order.)

Click the four buttons beneath the lit lightbulbs to match the patterns.

First, turn them all off and the middle light glows purple.

Then, click the 4th, 3rd, 2nd, 4th, 2nd, 1st, 2nd, 4th buttons from the left.

The porthole slides open and you can crawl through to a room with laser sensors. Somehow this doesn't feel like much of a challenge, so why not go forward?

Having dealt with a laser trap before, you confidently duck beneath and between the beams to a blank stone tablet with a clear gem which comes off easily. Is it valuable, or perhaps completely worthless?

Turn around and make your way back to the porthole and into the basement. There's one more thing to do here.

The purple buttons match those on the five-button safe, and the marking on that safe matches the open packet you have in your hand (which held the yellow key), and the packet seems sized to fit one light bulb. But which one?

There was that one bulb that turned purple. Light bulbs don't just glow purple, that one seemed to go beyond... beyond violet? Ultraviolet!

Place the packet over the middle bulb, and turn the other bulbs off again. The blacklight reveals a fluorescent clue on the packet, so use that clue to unlock the matching safe.

Labeling the buttons A, B, C, D, E clockwise from top, you need to push the EBDACDEA buttons.

Push those buttons to open the safe and get a figurine that's even larger and more brownish than the others.

The figurine slots in your inventory suggests that one is missing, which reminds you of some unfinished business in the previous(yellow) room.

So you go back there, and the four-digit safe is still locked.

All those nails and all those loud sounds remind you of the nails in the wall in this room, so hammer them in.

Ah, all straightened out. But you still need to find a digit code, and there are no digits to be found.

The digits are on the grid in the next room, so go over to the pink room and examine it.

The tips of the nails poke sharply out of four circles in the grid.

The numbers in those circles are, from top to bottom, 7, 6, 9 and 4.

Matching that to the heights of the safe buttons gives you the code 9476.

Enter that in the safe (you might want to mute the sound for this), and it opens up so you can get the last figurine.

The green statue wants a mask, but the mask isn't ready. First, you need to fill its forehead hole with the hexagonal (bipyramidal) gem.

The mask shoots spikes out the back! Carefully place it on the statue's face.

Next, you need to place all four figurines in their holes. Obviously, the largest figurine should go in the largest hole, right?

You place the figurines in descending order of size, but the button still does nothing.

That's because the order is wrong. Or more accurately, one of the figurines is wrong. Why's the largest figurine not smiling?

Turn him over to find a hole in his back. So fix it by using the triangular block on it.

It doesn't fit? Hammer it in!

The large figurine splits apart so you can get a tiny golden figurine. He's smiling!

Now place the creepily smiling figurines in their matching slots, and push the button in the base of the green statue.

That wasn't a base at all! The statue rises from the floor and the rest of him comes into view. What did that do?

The pink poster indicates that light reflected off a mask should travel through holes into a dark room. You can see all the holes involved, so it makes sense to assume the dark room is behind the rectangular ceiling hole.

Either way, you need a source of light to shine on the mask.

So point your flashlight at it to do the thing.

As the now-blue light enters the dark room, it (lights up and) turns on the machine under the rectangular hole in the pink room. So walk over to the pink room.

The machine that just turned on has moon and sun buttons, and through its glass you can see hexagonal and circular holes joined by a red arrow, beneath which a miniature smiling green man holds a key.

So use the appropriate clues to unlock the machine.

The laser corridor has a circular hole at the entrance and a hexagonal hole (on the tablet) at the other end.

From the latter to the former, the 1st, 2nd, 4th, 8th laser devices are off.

Would those be moon or sun?

The posters at the door show a standing man in the day and a crouching man in the night.

Since you can only stand when the lasers are off, you should press the sun button for those lasers.

So press the RRLRLLLRL buttons, and the machine opens up, and you can finally take a bluish key from the man inside.

A familiar sight greets you as you enter the door: a stone tablet with a sapphire and a geometric clue over a sequence of unusual symbols. On the right is a stopped clock and a projector with a slot for a flashlight. On the left is a safe with white and black buttons.

Turn left to find a machine with a TV screen! All it displays is a colored grid. On the right, there's a safe with a simple keypad and some sort of wireless symbol.

Turn left to find the doorway back and a light switch (button) next to it which you don't need to press yet. There's a projector screen but it's both raised and tied shut. Below that, an Othello board has too many squares, one of which is red. (And some of its pieces look different...) It has cardinal directions printed on its edges, though not exactly how you'd expect. There's also a downward-pointing button next to the board that doesn't work.

Turn left to find a black door with a simple device in front. The device is labeled with weird red symbols, and has a metal cover with a button beneath that doesn't work. Next to it is another switch on the wall labeled with weird symbols above a locked purple panel. The switch is missing some sort of handle, and so you don't have the leverage to flip it.

Let me just save you the trouble of poring over your codebook: the text on the switch reads CLOCK ON OFF, that on the door reads LOCK, and that on the tablet reads NW→SE.

Use the clue from the tablet and game board to unlock the two-button safe.

The board is missing precisely one piece out of 81, the piece that belongs in the red square.

The tablet tells you to place a black piece there, but you don't have it.

But if you did place it there, several white pieces would have to be flipped to become black, and then the pieces along the NW-SE (LL to UR) diagonal would be WWBWBBBWB in color.

So click the LLRLRRRLR buttons and open the safe to get a roll of vinyl tape.

You'll need to both reach the projector screen and untie it... at the same time.

So combine the Cutter and Reacher (in either order), and then tape them together.

It's a little unstable, but good enough to cut the screen loose, and then you quickly separate the two treasures again.

The screen's still up there, so push the downward-pointing button on the wall to lower it.

Place your lit flashlight in the projector, and push its button to release light from the top, trapping the flashlight inside.

Now all you have to do is dim the lights.

Turn off the lights (and the TV) by pressing the button next to the doorway.

Then look to the screen to find a drawing of a hammer over some coded text.

When you're done, turn the lights back on, then turn off the projector and retrieve your flashlight.

Use the hammer on the TV screen that displays the colored grid. It doesn't break, so keep going until you've hit it twelve times. (The counter resets if you back out, or save and load.)

The cover flies off the front and onto the floor, so you pick it up and find that it has buttons. It's a remote control!

You can use the remote on the TV to turn some squares red and remove some blue squares, and then you can see some sort of video going on behind the colored squares.

Maybe your remote's not set correctly? After all, there are 20 buttons there that you can turn blue (in addition to the five that are stuck on blue). You can only activate two of those at a time though.

You can also use the remote control to activate the keypad, which accepts up to six digits of input.

So you can press up to two buttons on the grid of the remote control. Which two should you press?

There's a different number of squares of each color. The only color that covers exactly two squares is black.

So press the matching buttons (2nd row, 2nd column, and 4th row, 5th column) on the remote control, and then use it on the TV again. Almost all the squares are gone, and you can watch the video quite comfortably.

The scenes in the video are:

• A bookshelf sliding and suddenly stopping, losing most of its books.

• A stone head draining water into an overflowing tank whose front falls out.

• An accordion device puffing smoke.

• A female statue holding up different numbers of fingers on each hand.

• Shurikens flying across a broken machine and onto cracks on the opposite wall.

• A dung beetle rolling a ball of dirt, and then giving you a silent look.

So use the clues from each scene to unlock the (activated) keypad.

The books on the shelf form a 7, the balls from the tank form a 2, the accordion smoke forms a 3, the statue holds up 8 fingers, the shurikens fly into cracks that form a 6, and the beetle moves in a path that's shaped like a 4.

So enter 723864 in the keypad. The TV turns off (but you can turn it back on and rewatch the video), and the purple panel opens up so you can get a tiny lever handle.

So insert the handle into the wall switch, and flip it down.

A panel opens beneath, where two doors with semicircular handles are surrounded by - and + markings above shortened levers with familiar-shaped holes, and a clue with an arrow from 4 to 12.

Use the screwdrivers on the holes, and now you can click the red arrows that showed up to turn the circular centre clockwise and counterclockwise.

Remember that the lever you flipped controls the CLOCKs. So watch each of them carefully, and use their clues to unlock the panel.

All seven clocks are now running, even if they show the wrong time.

But if you wait a bit and pay attention, you'll find that two of them run backwards!

(Since the clocks only run when the game does, you can check most of the clocks by loading an older saved game in a new tab.)

The clocks, in the order that you find them, are:

Green: 4 sides, ticks forwards
Gray: 8 sides, ticks backwards
Brown: 12 sides, ticks forwards
Yellow: 6 sides, ticks forwards
Pink: 10 sides, ticks backwards.
Black (basement): 9 sides, ticks forwards.
Blue: 5 sides, ticks forwards.

But how does that give you a code?

A clock that ticks forwards has hands that move clockwise, and you rotate the disc on the panel clockwise by clicking the right arrow next to the +.

So the clocks with 4, 5, 6, 8, 9, 10, 12 sides tick in the +++-+-+ directions.

Click the RRRLRLR arrows to open the panel, which now has six slots shaped like different keys. Next to it, the previously LOCKed panel now shows green symbols and has a row of six keyholes.

Retrieve your screwdrivers by clicking on them.

Go back to the main room and pick up 6 keys from the keyholes next to each door.

Other than the color, the only difference between the keys is the shapes of their tips.

The brown, gray, green, blue, pink, yellow keys (that's the order that they appear in your inventory) fit in the LR, UR, UL, R, L, LL key slots in the screwdriver pane to form the letters NKOUCL in the spaces.

But placing them there does nothing, because the keys belong elsewhere.

6 keys for one unlock? Sure, but you have to get them in the right order.

To spell UNLOCK, you have to use the blue, brown, yellow, green, pink, gray keys, which are in the 4th, 1st, 6th, 3rd, 5th, 2nd spots in your inventory.

Insert them in the panel, and push the upward-pointing button. Sure enough, the black door rises up to let you into a small room with a single green seal in it! So click on that.

As the light shimmers, you find a very large throne in the room, and a silhouetted crowned figure sitting in it.

Unlocker appreciates a good challenge after being suddenly awoken from his long slumber. Of course, he's a master at defeating locks, and he invites you to watch.

So use him on the final door, and he invokes the power of his Lemegeton. Wait, doesn't that book have demons in it?

He summons forth four leaders of Hell: Forneus, Bael, Paimon and Eligor, and they cooperate to forge a skeleton key!

It opens the final lock, so you thank him, he praises you for your faith (but his long-windedness gets cut off by the save button), and then he gives you the final treasure, a plain old key.

"It can open things that are shut, and it can shut things that are open."

And with that unhelpful quote, he fades away to take a rest. Not a very active guy, huh?

(Now that you've completed all the puzzles, you might want to save your game before the ending.)

You proceed onward to the Grail. (Oh, did you remember all your treasures? Can't possibly leave a Lighter or Driver behind now!)

But wait, it's just a white room with a poster and pedestals! The huge double doors slam shut and fade into the wall, trapping you inside. There's no turning back now.

You get an ominous feeling as you look around the room to find seven empty plinths. The only other thing in the room is a clue on the wall showing a tree, or perhaps a root, or perhaps a map, with various circles at the ends of several paths.

(Warning: This is the last chance to save the game. If you intend to rewatch the ending, make sure you save.)

In clockwise order on the poster, there's a large circle with the Holy Grail, then a circle with a long bendy path, then circles with a crack, a cut line, a keyhole, a plus and minus, the color black, and text-like symbols.

So make full use of your treasures to match the clues.

The poster is a map of the room, showing the three plinths on each of the left and right walls and one on the wall opposite it. Each circle on the clue matches a different treasure.

So place, clockwise from the poster, the Reacher (2), Hammer (6), Cutter (1), Unlocker (7), Driver (3), Lighter (5) and Decoder (4) on the plinths (from those last seven slots in your inventory).

The room goes dark and all the treasures glow. So you turn to face the poster, and a column of light pulsating in front of it.

You click on the column of light, and the Holy Grail appears and you pick it up. But does it really work? There's only one way to find out. So you make a wish.

"O Holy Grail, get me out of here!"

In a flash, you find yourself surrounded by sand. A stone eye looks down from above a familiar doorway.

The Grail works! Wait, where did it go?

"It's not here." You look towards the unknown voice, and the eye projects a silhouette of a knight with a swan who introduces himself as the Grail's guardian.

He reminds you about something you knew from the very start: nobody may pass the door unless empty-handed.

Just as written in the old texts, it's impossible to leave with the Grail.

Well, you're empty-handed, so why not go back in for another chance?

"That's not possible. Someone like you who could possess the Grail, even for a moment, would not be empty-handed."

But it's as if it never happened, right?

"Well, you'll see very soon. Something that you have..."

The guardian fades away and the eye shuts. Was it all for naught?

All that hard work! All those puzzles! All the-

Hmm, could that be it? The thing that you still have? That's right, it never remained in there.

Alright, time to go home! Man, this path is long.

Erm... why's everybody here? What are they doing?

The silhouettes ask you to wait for them so they can set off with their new master to their new castle.

Wait, they're all moving into your six-tatami room. It hasn't even been dusted yet! It can't be. The things you gained... are these guys?

They're all ready to go, and even have tonight's feast planned out. Alright then, I guess.

The screen pans up and fades out. The end! Thank you for playing!