Detective James Knight 's last-minute assignment to the Independence Day shift turns into a race to stop an unbalanced ambulance EMT from imperiling the city's festivities. The misguided vigilante, playing cop with a stolen gun and uniform, has a bank vault full of reasons to put on his own fireworks show... one that will strike dangerously close to Knight's home.

Mack is a former soldier who, after the war, moved to a town with a nuclear power plant, where nearly everybody works. Life is peaceful for him there, until a gang of mercenaries led by Ron storm the reactor and take everybody hostage, including a group of children on a school trip. Now Mack is in a race against the clock and must use his military training to defeat Ron before he puts the reactor into meltdown. Along the way he discovers Ron’s motive, which unravels a greater secret Mack’s town is hiding.