The plot of the game involves the player (Peterson) taking part in a STAAR (Strategic Tactical Advanced Alien Response) military incursion to prevent aliens, known as the Kronn, and alien-created zombies from taking over the Area 51 military facility.

The plot of the game involves the player (Peterson) taking part in a STAAR (Strategic Tactical Advanced Alien Response) military incursion to prevent aliens, known as the Kronn, and alien-created zombies from taking over the Area 51 military facility.