*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.
*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).
*Place a portal on the wall near the third turret. Place 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.
*Place a portal under the turret and continue following Wheatley. Enter the elevator at the end of the catwalk.
*Wait for the elevator to stop and go through the door.
}}
== Video walkthrough ==
== Video walkthrough ==
Revision as of 21:52, 22 July 2011
“I can't get over how small you are!” This article is a stub. As such, it is not complete. You can help Portal wiki by expanding it.
Chapter 4 - Test Chamber 21
sp_a2_bts1.bsp
This is the thirty-first 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.