The first Portal 2 downloadable content pack will be released on the 5th of October for Xbox 360, PlayStation 3 and PC.

Called Peer Review, the DLC features a new co-op test track wherein Aperture robots P-Body and Atlas set out to defy GLaDOS.

Additionally, there’s a new singleplayer and cooperative challenge mode, and online leaderboards have been implemented.

And the best part: it’s free.