Off the coast of Delaware sits the cozy Plum Island where two families are locked in a struggle for power, as it has been for generations. The O'Flynn's, headed by patriarch Patrick O'Flynn approach the zombie plague with a shoot-to-kill attitude. The Muldoons, headed by Shamus Muldoon, feel that the zombies should be quarantined and kept "alive," in hopes that a solution will someday be found. The O'Flynn's, who are clearly outnumbered, are forced to exile Patrick by boat to the mainland, where he meets up with a band of soldiers, headed by Guardsman Sarge. They join forces and return to the island, to find that the zombie plague has fully gripped the divided community.