Full screen ed.
Something has gone terribly wrong at a remote scientific research station on Mars. All research at the station has ceased and communication with Earth is failing. The messages that do get through are becoming more frantic and less than comforting. It's a level 5 quarantine and the only humans allowed in or out of the area are the Rapid Response Tactical Squad - hardened Space Marines armed to the teeth with enough firepower to destroy a legion of nightmarish creatures.