It’s vacation time for outdoorsy Chicago man Chet Ripley, along with his wife, Connie, and their two kids, Buck and Ben. But a serene weekend of fishing at a Wisconsin lakeside cabin gets crashed by Connie’s obnoxious brother-in-law, Roman Craig, his wife, Kate, and the couple’s two daughters. As the excursion wears on, the Ripleys find themselves at odds with the stuffy Craig family.

Every six hundred years, a great evil has the opportunity to escape and unleash Armageddon. A group of five stones has the power to either free the evil, or banish it for another six hundred years. An order of Druids battles with a Warlock determined to unleash his father upon the world.