Will Ferrell co-writes and stars in this comedy about two losers, Brennan Huff (Ferrell) and Dale Doback (John C. Reilly), who become stepbrothers after Brennan's mother Nancy (Mary Steenburgen) marries Dale's father Robert (Richard Jenkins). Because neither man has ever got around to leaving home despite his advanced age, the two now find themselves living together. After taking an initial dislike to one another, they eventually become united in their hatred of Brennan's successful but mean older brother Derek (Adam Scott), and come up with ever more elaborate schemes to knock him off his perch.