Test Chamber 9

Player 1: Place a portal on the wall of the light bridge and look up and to your left at the three turrets. Place a portal on the wall panel in view to create a light bridge barrier for protection.

As you ascend the funnel, place portals on wall panels to create protective light bridge barriers against turrets hidden in crevices.

Player 2: At the top, step onto the platform near the vertical excursion funnel. Look for yellow wall tiles to your right and place your excursion funnel portal on the large wall panel.

Jump into the nearby vertical funnel with Player 1 and ride it to the next platform.

Once you drop down, aim up and place your funnel portal on the wall panel above.

Head up the stairs with Player 1, jump into the funnel, and then jump out at the end onto the other platform.

Player 1: Go straight ahead and look through the broken panels to the vertical excursion funnel to your left. Place a portal here and on the wall panel to your left.

Player 2: Look down through the broken panels to the light bridge on the lower ground. Place your first portal on target. Run around the corner and look for turrets to your left, past the ledge. Block them off with a light bridge on the wall panel.

Both Players: Jump into the excursion funnel and ride it to the wall at the end.

Player 2: Place a light bridge on the wall near where the turrets are coming from to create a barrier that will knock them off the conveyor belt.

Player 1: Look for a small square-ish room with a broken roof below. Zoom in to find a wall panel and place a portal on it.

As you are transported, Player 2 should look for a thin rectangular panel behind a metal girder and place a light bridge there to block turrets.

When you reach the end, hop off towards the office and turn right when you enter. The optical disc is on a table at the back.

Pop the optical disc into its slot to finish Course 4.