Flynn Jefferson's father has hooked up with Casey York's mother, who also happens to be their history teacher. With home life being hard for Flynn, he gets into trouble for punching a fellow student, so their parents decide to take them both away for a break. Refusing to go unless their friends can come too, they grumble the whole way, with the trip leading them to the small town of Eagle Ridge where they meet a grizzled old man who has quite a story to tell. About a plague of zombies rising on Halloween night. Which also happens to be a blood moon...

Ignoring the story, they settle into their cabin and soon find strange symbols painted under their beds, on the window shutters, and on every store window in town. But it's the odd wooden box that Casey finds that leads them down a very dark path of discovery.

With the girls enamoured by Chatan, the local artist and campground manager, it's up to Flynn and his friends to find a way to defeat the monsters that have risen in the night. But they may just need Casey's help, especially when they find out she's intricately woven into the creatures' pasts.