In an eerie country house, a cruel old man is decapitated. When Peter Coffin's mysterious great-uncle Tobias summons the family to his manor in the wilds of Michigan, his aunt warns him to stay away. Peter goes anyway, arriving at the edge of the sprawling estate well after midnight. Wading through the muck in the darkness, he passes a fearsome figure on the road, and when he arrives at the front door, he is greeted by cousins bearing shotguns. An ax-murdering madman is on the loose, but just as dangerous are the creatures Peter will encounter inside the house: his family. When old Tobias is murdered, both his head and his will go missing. The police suspect the ax killer, but Peter knows better. After all, if there is one thing his aunt has taught him, it is that you should never trust a Coffin.