An insanely easy ‘test’, walk past the red button on the floor and look down into the pit in the middle of the room (to the right). Fire a portal on top of the Companion Cube and turn around and look behind you.
The Cube will now bear sitting near the button for you, simply pick it up, set it down on the red button and the exit will open!
Welcome back to Aperture Science, a world where your Companion Cube isn't you're only company. Take control of Chell once again in Valve's sequel which takes you on an humorous and puzzling adventure and in our detail-packed guide we'll show you:
How to solve every test chamber first time.
Conquer every co-op chamber with a friend.
Loads of High Definition screenshots and videos showing you the solutions to every single chamber.
High Definition strategy videos for every achievement in the game.
Uncover all of the hidden secrets and Easter eggs.