Activision has unveiled a new trailer for their upcoming Black Ops Escalation Map Pack featuring the new zombie mode titled “Call of the Dead.”

The trailer confirms all new playable characters, including Sarah Michelle Gellar, Robert Englund, Michael Rooker, and Danny Trejo. Set in a ice-covered remote Siberian island and inspired by legendary writer and director George A. Romero, players will have to survive an invading army of bloodthirsty Soviet zombies.

The Call of Duty: Black Ops Escalation Map Pack comes with four multiplayer maps and the new zombie mode. It’s scheduled to release May 3 for Xbox 360, with the PS3 version hitting sometime after.

Watch the trailer below.