In friendship, they are linked. In eternal friendship, they will suffer.
When a group of popular high school students decide to get matching henna tattoos at the Grimwood Halloween Festival, they had no idea what fate had in store for them. It was just a Native American symbol for friendship, they thought. But friendship in a place like Grimwood, as it turns out, transcends all things -- even death. And when one of the members of the group dies, then rises, they realize it's more serious than they could have imagined.
The teens keep dropping and rising one by one- putting everyone around them in danger of succumbing to their sharp teeth and their curse. It's up to the others still alive to solve the problem before it gets vastly out of hand and they bring on a worldwide accidental zombie apocalypse.