The wildlife is wild, but his brother-in-law in unbearable.

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.