The Dillon sisters don't necessarily like each other, but they'll always look out for each other. Leah, ex-military, has just picked up her career criminal sister, Vee, from prison, when they learn that their troubled older brother, Michael, has burned down a warehouse owned by a notorious gangster. The siblings find themselves on the hook for an outrageous sum of money and have only two weeks to get it or Michael will die. So with nowhere to turn, they decide to rob the town's biggest bank. The heist starts off smoothly, but mayhem ensues when the defiant bank manager resists helping them and one of the tellers tries to escape. The Dillons now have an unconscious bank manager and a woman fighting for her life. They waste no time in heading downstairs, but once they enter the basement, they witness the inexplicable, hordes of hellish ghouls appear, bent on violent, bloody revenge. They want to abort, but somehow the police have caught wind of the heist, so they're left with a terrible choice: face the 100+ heavily armed FBI agents camped outside, or confront whatever is in the vault beneath them. They don't want to stay, but they can't leave. What hell lies in The Vault?