Warnings Active: Cube Dispenser, Orb Hitting Body, Orb Receiver, Dangerous Water, Jumping Into Portal, Flying Out Of Portal, Don't Drink The Water

In this puzzle, there are two ways to do this: the way you are supposed to do it, and the quick way. Since this is, after all, a walkthrough, I'll begin with the regular way. The lift in the middle requires power; this is the goal of the exercise. To your left is a pit and a receiver; to your right, a closed door with a button. Go to the right, and the pit will unfold into stairs. After you ascend, the stairs will lower back into a pit. To the left of the receiver (if you face it from the direction you came) is a raised set of boxes with a cube on it. These boxes are made of portal-proof substance, so make a portal on the wall facing the cube (it should have some telltale stains on it) and then make another in the pit. Jump into the portal in the pit to launch yourself at the box, as done before. Now the pit will permanently become stairs.

Walk down them and put the cube on the button. In the room past the door you will find two raising and lowering lifts that descend into and rise out of a pool of dangerous water. Time your jumps to cross - you can also make a portal, but keep in mind you cannot return using one. Once crossed, make a portal on the wall with the scorchmark. Hop back over the raising/lowering platforms, walk back to the receiver, and make the other portal above it. Now the lift will be active; ride it up to progress to the next level.

The SHORT version of this is to make a portal in front of the raised lift, climb the stairs, and then make the other portal in the pit, using the momentum to launch yourself up to the top of the lift.

Portal Walkthrough