Tom Baker and wife Kate, hoping to bring their family together for a memorable summer vacation, take their 12 offspring to the rustic Lake Winnetka. But their retreat soon becomes cutthroat when they enter into a competition with the over-achieving members of a large family headed by Tom's long-time rival, Jimmy Muraugh.
Set in the 1970s in a metropolis called "Bay City," this is the tale of two police detective partners, Ken "Hutch" Hutchinson (Wilson), and Dave Starsky (Stiller), who always seem to get the toughest cases from their boss, Captain Dobey, rely on omniscient street informer Huggy Bear (Dogg) and race to the scene of the crimes in their souped-up 1974 Ford Torino hot rod, telling the story of their first big case (as a prequel to the TV show), which involved a former college campus drug dealer (Vaughn) who went on to become a white collar criminal.
The six high school students who ran over a man on a sharp curve the year before think the killer is out for revenge, but sweet and innocent Cindy Campbell believes that the madman might just lurk a lot closer to home.