In the heart of Boston, following the devastating events of an alien invasion, history professor Tom Mason and his sons Hal, Matt, and Ben are just trying to survive. After an extreme firefight with the aliens, Ben gets kidnapped. Determined to get his son back, Tom joins forces with the Second Mass, a militia group that is taking the fight

Catastrophe approaches as Dai makes it back to camp, only to deliver bad news . . . news that could lead to a final stand for the 2nd Mass.