The Weighted Companion Cube is one of the most iconic parts of the original Portal (a game with more than a few iconic aspects.) Despite the cube’s staggering popularity with Portal‘s community, it was surprising that, other than a few sparse mentions of it, Portal 2 had a notable Companion Cube absence. In fact, most of the things that made Portal iconic were reduced to smaller references in Portal 2 to make way for the sequel’s own iconic moments.
The Companion Cube is only featured in one test in Portal 2, but there’s something special about it: the cube can actually be taken out of the testing area allowing the player to hear some secret dialog and get the “Preservation of Mass” achievement. In Portal: Companion Collection recently released for the Switch, players are able to unlock the achievement thanks to the in-game achievement list.
Stealing the Companion Cube in Portal 2
As mentioned above, there’s only one test chamber in Portal 2 that features the Weighted Companion Cube. To unlock the achievement and hear the secret GLaDOS voice line, you’ll need to make it to Test Chamber 7, it should be a few chambers after you and Wheatley wake up GLaDOS. When you enter the chamber, you’ll notice the Companion Cube is directly across from the entrance separated from you by a laser. After jumping over the laser to grab the cube, GLaDOS will fizzle it as soon as you pick it up. Do this a few more times until you’ve got a real grasp on the cube.
Solve the puzzle as normal: put the cube in front of the laser dropping the platform, get on the platform and put a portal underneath the cube and then on the wall to move the cube and raise the platform: easy stuff. Once on the top section of the chamber, put a portal on the rightmost slanted wall and then one underneath the cube. This should cause the cube to be on your level. Put a portal on the floor far below you, grab the cube, then jump through the floor portal causing you to fly through the air out of your slanted tile portal. The setup for this can be seen below:
Once you’re up on the higher section of floor with the cube, drop it on the switch. You should notice that the door above you to the right will open. This is how the puzzle is normally solved, but what you’ll need to do is put the Companion Cube in the corner of the switch as close to the door as possible.
With the cube on the switch close to the door, turn back around and place a portal on the leftmost slanted tile and one on the bottom layer of floor. Jump down through the floor portal and fly towards the exit door. Here, GLaDOS will remark on how there’s no emancipation grid in this chamber meaning that test objects could theoretically be taken out of it. Unbeknownst to her, that’s exactly what we’re planning on doing.
Instead of going through the exit door, walk towards the cube without jumping down to the lower level that it’s on. If you’ve placed the cube close enough to the wall, you can crouch (hold the B button) and grab it (hit the X button.) With Companion Cube in hand, exit the chamber to pop the achievement and hear GLaDOS’ secret dialog.
Unfortunately, this is the end of the road for the Companion Cube in the series as GLaDOS will fizzle it despite the lack of emancipation grid. RIP Weighted Companion Cube, you will be missed.