Hopping Between Holes: Portal 2's Debut DLC Pack Launches For Free Next Week.

The DLC will be available for free and continues the tale of P-Body and Atlas as you attempt to make your way through a new set of co-operative levels — and come into contact with the devious GLaDOS once again.

The DLC also boasts a new single-player and co-operative challenge mode, with leaderboards that allow you to compare your records against the Portal community.