Portal 2 Chapter 4 Test Chamber 21 (Escape)

This is the thirtieth level of the game, and the final part of Chapter 4. This level is set within a Test Chamber and the maintenance areas of the Aperture Science facility. This level advances the central plot, and does not contain any significant Portal-related challenges.

Hazards

 * Goo
 * Turrets
 * Neurotoxin

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Intended Chamber Solution

 * Place a portal on the wall where the Hard Light Bridge ends and the other one on the left side of the exit.
 * Go through the portal and push the Switch.
 * Continue to walk to the cube.
 * Put the cube on the button.
 * Use the portal again to proceed to the chamber lock.

Actual Course of Action
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 * Wait for Wheatley to open the wall and run to the Maintenance area.
 * Run to the left and continue forwards.
 * Turn right on just before the catwalk ends.
 * Turn left and jump down. Continue by to the right up the stairs.
 * Run forward as much as you can. Turn left and continue running.
 * Jump down on the left side.
 * Use the Bridge and run away from the Chamber until the Bridge disappears.
 * Turn to the opposite direction and continue running.
 * Jump from the catwalk to the area between chambers and run forward until you get to the wall.
 * Pick up the turret and knock over the turret behind it.
 * Turn left and go behind the tube and knock over the third turret.
 * Let go off the turret (make sure it gets knocked over).
 * Open a portal on the wall near the third turret. Shoot the other portal behind the panels where the third turret is. Go through the portal.
 * Run to the right and follow Wheatley until a turret is revealed on the left.
 * Get rid of the turret by using a portal and continue following Wheatley. Enter the elevator at the end of the catwalk.
 * Wait for the elevator to stop and go through the door.

Test Chamber 21


Involves Hard Light Bridges. Midway through the test, Wheatley turns off the lights and reveals himself. He tries talking in a bad American accent, thinking it is beyond GLaDOS' range of hearing, but realizes that is false and just breaks out of the chamber with Chell.

If you use a cheat code to spawn a sphere (a testing element cut out of the single player game) or cube on the button, the door will open, but the lights won't go out. Then use the bridge to go through the door, and then you'll find yourself in a pitch black room.

Additionally, if the player does NOT escape with Wheatley immediately, GLaDOS activates neurotoxin emitters in this chamber in an attempt to kill you. The neurotoxin is out of range as soon as the player leaves the chamber, however, since it closes itself.

As Wheatley and Chell make their way across the catwalks, Wheatley reveals the next part of his escape plan. They will take out the turret and neurotoxin production plants, then make their way back to GLaDOS's chamber and confront her a second time.

Test Chamber 22


As Wheatley leads Chell away from the test area, GLaDOS claims that Chell had escaped just before she reached the final test. A wall opens, revealing the "Test Chamber," which GLaDOS says "is an easier way out that whatever asinine plan your friend came up with."

If the player enters this Test Chamber, they will realize it was a death trap, as the wall closes behind them while the room fills with neurotoxin, which will kill the player within 5 seconds of entering the "chamber". There is another door on the adjacent side of the entrance with plants visible through it, but the door shuts itself when the player gets close to it, due to GLaDOS fizzling the Weighted Companion Cube on the button that keeps the door open. There is no way to escape from the "chamber" except by reloading from the last save point. There is also a series of white panels making a heart shape on the wall.

Whether this trap was actually Test Chamber 22 is left ambiguous as GLaDOS drops several hints that Chell will have to test for the next 60 years before she dies. On the other hand, she implies she was going to kill Chell after she completed Test Chamber 21 and had apparently finished building ATLAS and P-body to replace Chell by then, so it's possible this was Test Chamber 22, or at least had the same function.

Going into this chamber unlocks the achievement "Good Listener".