Warnings Active: Cube Dispenser, Cube Hitting Head, Turrets

Now we first encounter the deceptively pleasant turrets. Ignore the computer's explanations of this chamber as a mistake, as you will encounter these later. Here are the basic rules of the turrets: they will deploy whenever they see you and then riddle your body with bullets. To destroy them, you must knock them over; the turret will spray wildly and then deactivate. You cannot really trick a turret into shooting itself by confusing it with portals, because as long as its lasers can touch you, you can be shot at. Thus, the best strategy is to get behind it.

You start out behind this first turret; walk into it or pick it up with the use key (default "E") and then drop it. Walk into the corridor and notice the laser going across your vision. If you walk into it, the turret will shoot. Peek out of the doorway and make a portal above or behind the turret. Do it quickly so the turret cannot lock onto you. Make another turret on the wall out of the way of the laser, or when you go through the turret will simply shoot at you. When behind the turret, knock it over. Now advance and there will be a turret on a raised staircase; make one turret on the wall behind, above, or next to it and the other out of its view again. Get behind it and knock it over.

In the next section, we are given two cubes to work with. Look carefully at the first turret visible and you will see a red x on the ceiling above it. Make a portal there and another out of its reach (but in yours). Put a cube through the closer portal and it will drop onto the turret, destroying it. Do the same for the turret around the corner (you need only move the "ceiling" portal to the red x above the second turret. Now, with the two cubes out of the way, notice the torn grating and crawl into the first crawlspace; this isn't necessary, but it offers a glimpse of the mysterious circumstances surrounding the project. The scrawls also indicate how to defeat turrets - namely, dropping cubes and redirecting orbs. Remember the second one, as it will come in handy in a later level.

Now, pick up one of the cubes and advance with it held out in front of you (crouching is also advisable). Using the cube as cover, walk up to one of the turrets and swing the cube sideways to bash it. Do the same to the turret facing away from you. Look into the room with the radio, the tools, and the apparently broken dispenser; it also hold a multitude of cubes. These are our weapons. Notice again the red x marks on the ceiling in the room with the three turrets. Quickly dart out and make a red x above the first visible turret, then make another portal and drop a cube on its head. Sidle into the room with the turrets and subdue the one facing somewhat away from you. Then, either make a portal above the final turret and drop another cube on it, or pick up a cube and use it as a shield (a method which wouldn't work against all three due to the fact that you can only cover one side at a time). Either way, pick up a cube and put it on the button.

The door will open and reveal another turret, which may get you killed if you rush in without checking. Shoot a portal through the fence onto the wall behind it and another within your reach. Now look to your right and make another portal out of the view of the turret. Walk through and subdue this final turret. You can also, if you are so inclined, attempt to carry it through the particle field, which will vaporize it. Walk into the elevator.

Portal Walkthrough