A meteor that looks like a vertebra hits the earth and people start turning into zombies. A group of survivors hole up in a bunker on top of a hill and try to formulate a plan for survival. One of the woman is a porn star and talks repeatedly about it, which makes you pray the zombies will soon eat her.
While there are zombies outside the compound, what the survivors discover is that the meteor also had some sort of alien life form which incubates in the zombie host. This leads to a really disgusting scene, which I must confess was original. I've never seen an alien sack that made me so squeamish.
The characters are annoying and the explanation as to why this particular group did not turn into zombies is incredibly lame. Also if you're looking for zombie action, there's not much. The carnage that does occur is due to the stupidity of the characters, so you don't feel sorry for them.