Player 2 : Run to the centre of the room and pick up the Displacement Cube, aim it so you're directing the beam into the receptor on the left-side of the room (raising the spiked barricade).
Player 2 : Once player 1 is waiting on the second platform, rotate the beam to your right and line it up with the receptor over on the wall here. This'll will cause player 1's platform to drop as the spikes raise upwards.
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.