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 later 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

Walkthrough

 * 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.