Press the small red button outside of the cube room first. To solve this puzzle, you need to get the cube onto the button and pass through the door. The first is the cube, the second is the big red button, and the third is the exit. There are three rooms, each with a corresponding button and important piece of the puzzle. This room will teach you a bit more about portals. Portals also disappear when you pass through. The announcer will note the Aperture Science Material Emancipation Grill, and you should too: you can’t bring objects through this particle field. The door will open, allowing you to continue.

Pick it up and place it on the giant red button on the floor. In this room, a cube will be dropped out of a tube in the ceiling. Once on the other side, walk around the glass box and through the door. Walk through it you’ll see that a portal has been created between the two spaces. The announcer will tell you that you can still continue despite a potential apocalypse. If you’ve played the first Portal title, you’ll recognize this room (and the next few bits of the game).

Head down through the rubble and you’ll crash into a small glass box. Once it’s time, Wheatley will tell you to be off.

Portal 2 incinerator room