Valve keeps plenty of secrets from the world, locked away and tied down with live, stripped wires above a shallow pool of stale water, surrounded by a moat of baby hippopotamuses -- but this secret got out. Turret Lullaby is a six-page Portal 2 comic that explains the birth of the singing turrets. We don't want to give it away, but it involves a baby, a burglar and a lot of bullets.
Portal 2 is the sequel to 2007's Game of the Year and draws from the award-winning formula of innovative gameplay, story, and music that earned the original over 70 industry accolades. Features single and multiplayer co-op modes.