For the patrons and staff at a dusty roadside diner, the day begins as usual, but when the phones go out and a sweet old lady goes on the attack, it's a harbinger of the terror to come. As the horrifying nature of the situation sinks in, help arrives in the form of the archangel Michael (Paul Bettany), who tells a pregnant waitress that her unborn baby is humanity's last hope, and he will do anything to protect it.