The game begins immediately following the conclusion of Riddle School 5, and sees Phil and his friends captured by the government following their adventure in space.

After gaining control of Phil, click the toilet lid to look inside.

Click the flusher handle on the inside front of the toilet to take it, then click the red arrow to return to the cell.

If you click the TV screen in the upper right, you learn the door code is 78255.

Use the flusher handle on the keypad to reach it.

Enter the combination 78255 to open the door.

Click the red to leave the room.

Click the arrow pointing to the blue rounded doorway to find the box room.

Click the top left piece of paper on the pin board to lift it. The papers are arranged in layers; you'll need to click the top pages to reach the ones underneath.

Once you reach the bottom, you'll find the key to the elevator. Take it, then leave.

Back in the hallway, go through the tunnel to the left of the box room.

Take the odd device on the wall beneath the "Goat: Man" sign to learn it's a "creature communicator". If you use it on the Goat: Man, you learn that he wants his enclosure to have fresh grass. You also learn that recycling falls through the pipe on the ceiling, which will prove a clue for a later puzzle.

Leave the room.

Back in the hallway, go left.

Enter the elevator.

Use the elevator key on the panel's keyhole to unlock it. Push B2. After arriving, go right.

Go down the middle tunnel.

Take the hose from the ground on the left, then use the creature communicator on the Mock Mess Monster to talk to them. Choose "Where did you used to live before you were put in here?" to learn that they long to return to their home. They also give you a keycard for the power room.

Choose "Communicate with you later", then click the red arrow to leave. Return to the elevator, and push the B1 button. Leave the elevator and go right.

Use the key card on the card reader to unlock the power room, then enter.

Click the Pipeline Shifter machine on the back wall.

You need to re: arrange the pipes so Messie can be flushed back to Mock Mess, like so:Treating the tiles as if they were numbered 1: 9, click 2: 5: 4: 7: 8: 5: 2: 3: 6: 9.

Use the flusher handle in your inventory to replace the missing FLUSH handle, then click it to free Messie. As he's flushed, he loses his top hat.

After the cutscene, leave the power room and go down the middle tunnel.

Use the creature communicator on the Negotiable Snowman and choose "It looks like you don't have a whole lot of hair." The Yeddy wishes he had more hair, and offers to give you a die from a board game if you help him.

Choose "Communicate with you later", then return to the elevator. Push the F1 button, then go right.

In the main hallway, go right to find Smiley's jail cell.

After talking to her, click her to talk some more, and choose "Could I have your hair spray?", and she'll give you the can.

Choose "Let's talk more another time" to exit the conversation, then return to the elevator and go back to B1. Go back to the Yeddy, and give him the hairspray; in exchange, he gives you the dice.

Go back to Smiley's cell on the 1st Floor. Talk to her, and choose "Do you know what the code for your door's dialpad is?". You learn it is 51333.

Exit the conversation, then click the keypad.

Insert the dice into the missing slot, then enter the code 51333 to rescue Smiley.

Go back to the elevator, and push F3. Go right.

Go through the rounded door to find the break room.

Click the hose in your inventory, then click the middle of the Chloro: Fill machine to attach it, then click the recycling bin to place the other end; the Chloro: Fill will rejuvenate the Goat: Man's enclosure below with fresh grass and daises.

Leave the break room and go to the elevator. Return to Floor 2 and go back down the tunnel to the Goat: Man.

Click the daisy at the bottom of the ladder to take it, then return to the elevator; go to F3, and right, into the cell area to find Zack, who is tied to the ceiling.

Talk to Zack, and choose "Do you know what the code for your cell door is?". He tells you that the digits are "12345, but not necessarily in that order", and proceeds to give the answer in the form of a riddle.

The first digit plus the second digit is equal to the third digit.

The second digit is two times the first digit.

The second digit is half the fourth digit.

The fifth digit is the sum of the first and fourth digits.

The answer is 12345; enter this into the keypad to unlock the door.

If you talk to Zack and choose "what are some fun facts about you that I don't already know?", you learn he is allergic to daisies, which causes him to sneeze and his flames to grow.

Use the daisy on Zack and he'll sneeze and burn through his restraints. He will then be added to your inventory, and follow you around.

Leave the room. In the hall, go down the middle tunnel to find the flying pig from Riddle School 3's ending.

The pig is unable to fit between the bars to escape, so use Zack on the wooden board to burn through it. After the pig flies off, take the feathers from the cage, then leave.

Return to the elevator and push B2. Return to Messie's enclosure.

Take the top hat, then return to the elevator and go to F1.

In the hall, go down the middle tunnel to reach the Bigtoe enclosure.

If you were talk to Bigtoe, you learn that he collects fancy hats. In your inventory, combine the top hat with the feathers to make it fancy, then give it to Bigtoe; in exchange, he'll give you a spare keypad.

Return to the elevator and go to B1. Go right twice to the cells, where you find Phred.

After you finish talking, click Phred and choose "Do you know what the code for your door's dialpad is?". He then shows you a piece of paper with what appears to be the word snoz written on it.

It doesn't actually say snoz; the n is really the number 17, bunched up. Properly spaced out, the paper would really read 51702.

Exit out from the paper and conversation, then use the spare keypad on the empty slot; click it and enter the code 51702 to free Phred.

Return to the elevator and push B2.

Go right twice to find a sentient security door.

Click the door; on seeing all 4 of you have escaped, the door begins acting erratically, and will rapidly open and close.

Use the elevator and go back to B1. Enter the power room and click the "Guard Door Power" in the back right.

You need to click the power button to stop the door when it's open. Once stopped, go back down to B2, and go through the now open security door.

The game will then auto: save, since the next room has a number of tricky puzzles a player might not be able to solve in one sitting.

After the cutscene, use the creature communicator on the slot beneath Diz; two panels on either side of the machine will open.

Click the left one.

To solve this puzzle, you simply need to click a white tile to cycle through all of the shapes, in order to match the example shown in the upper left, like so:Once you've matched it, click the grey arrow button to confirm; the next puzzle panel will unlock if done correctly. Click it.

To solve this puzzle, you need to change all of the lights from black to white. You can solve this multiple ways simply by pushing the top left, top right, and bottom right buttons in any order.

As long as you don't press the bottom left button, the puzzle will be completed.

With both of the left puzzles solved, click the bottom right puzzle panel.

To solve this puzzle, you need to first solve the simple math sums on the left, then click the green tiles to form the shape of the answers.

7: 0 = 7

8: 2 = 6

6: 6 = 0

It's simply a a matter of clicking the buttons to create these shapes:Once done, the final puzzle panel will unlock. Click it.

You need to re: create the colored shape seen in the top left by clicking the green triangles.

Treating the triangles as if they were numbered, click them in this order:With all the puzzles solved, click Diz to free him from the mind: reader device.

Out in the hall, return to the elevator and push F1. Go right and into the rounded tunnel to find the space: ship hangar.

Click the ship. An alarm will sound and Diz will escape without you, leaving you trapped in the facility.

After the cutscene, simply click the arrows to reach the sewer grate on B2, then click it to escape, ending the game.