Place portals next to the two other Switches and prepare yourself for the timed puzzle.
Quickly, press the Switch next to you, then the one on the other side of the ledge and pas through the portal to activate the last Switch. Then fire a portal behind and facing the Material Emancipation Grill, and the other where the High Energy Pellet is bouncing.
The pellet should reach the catcher. Now, grab the cube and proceed to the next room. Place the cube on one of the three buttons.
Go through the Portal Inquisition Field and cross the obstacle course, avoiding to be crushed as well as the Electricity Fields, in order to reach the cube.
Do the reverse course with the cube. This cube mustn't touch any Electricity Field or get crushed.
Place the cube on one of the two empty buttons, then go on the last one.
Try not to get crushed by the descending ceiling pistons. Exclusive to the Portal with RTX.
While exiting the Shaft
Use the path that Peter opens. You are now in the maintenance areas.
Shoot a portal on the angled panel and the other near you then go through. Before touching the ground, place the same portal as the previous under you.
With the momentum you gained, you should reach the upper floor facing the angled panel. Take the cube and come back at the bottom.
Put the first portal in the alcove and go through the other portal with the cube. Use the two cubes as stairs to reach the hole above the alcove.
Knock out the Turrets carefully using portals, then go to the door at the bottom of the room.
Quickly, open the door, move forward, take the turret and vaporize it with the Material Emancipation Grill.
