Red Dead Redemption: Undead Nightmare is the fifth downloadable content (DLC) pack released for Red Dead Redemption. It was released for the PlayStation 3 and for Xbox 360 on October 26, 2010. Undead Nightmare follows the exploits of John Marston, as he searches for a cure for an infectious zombie plague that has swept across the American Old West. Coincidentally, the original concept for Red Dead Revolver was a western-horror hybrid video game where Red Harlow fought zombies.