Their relationship on the rocks, a young Brooklyn couple heads to a remote B&B to work things out. But from the moment they arrive at The Happy House, it's one disaster after another, and they soon begin to suspect they've wandered into a real life horror movie. Events escalate from weird to terrifying as they contend with the house's batty owner, her imposing son, a moody Swedish lepidopterist, a pedantic English professor, an extraordinarily rare butterfly, the world's best blueberry muffins, a .44 Magnum, a demented serial killer and one very strict rulebook.