This is a sequel, continuation of one of the characters from DIARY OF THE DEAD, and also fits within the George Romero Zombie Universe. The first story concerns the fued between the O'Flynn's and the Muldoons on Plum Island, which is off the coast of Delaware. Patrick O'Flynn wants to rid the island of all the zombies while Seamus Muldoon wants to protect them in the hopes that there is some type of cure. The two old coots have been enemies since before they immigrated to America. Muldoon gets the upper hand in the first scene and banishes Patrick and a few other guys to the mainland.
Then we go to the story of Sarge Crocket, the leader of the military gang that had robbed the documentary filmmakers in DIARY OF THE DEAD. The group is still stealing. One of the guys, who has an internet connection, picks up a video sent by O'Flynn, about how Plum Island is a safe haven. So they go South and find O'Flynn, who wants to sell them a boat for "everything they have". They don't want to do this and so try taking a nearby Ferry. O'Flynn doesn't like this and there's a fight, though he's the only one on his side who stays alive. He ends up going with Sarge's group back to the island, where they find zombies chained up and doing their familiar chores. There's also O'Flynn's daughter, who rides by them on a horse. Only she's now a zombie as well.
This is an interesting movie, much more about the people than the undead, sort of like the comic THE WALKING DEAD. The movie is also a departure in that it has a matter of fact sense of humor about it, like when Sarge shoves a flare in a zombies mouth, then proceeds to light his cigarette from its flaming head, or when we see a guy fishing, only he's catching zombies that are walking on the bottom of the water. I enjoyed this, primarily because it continues the themes begun in DAY OF THE DEAD and LAND OF THE DEAD, with zombies beginning to think. Recommended.