Player 1: Make your way through the force field and into the other half of the room. You'll want your two portals on the angled wall panel in the left-hand corner and also on the angled wall panel in the lower right-hand corner of the room.
Now hit the red plunger and a Companion Cube will drop down onto the Arial Faith Plate, carrying it through the same portals you just passed through. As soon as the Cube nears you, grab it and then drop it down on the ground for player 1.
Player 2: Once player 1 has completed 1 'lap', wait for them to hit the Faith Plate in the water (the one that leads them directly into the wall panel). As soon as they hit the plate, press the plunger to release the Companion Cube.
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.