Harry Hinkle (Jack Lemmon) is one lucky guy! When he's accidentally clobbered by a 220-pound halfback, all Harry suffers is a slight concussion. All, that is, until Whiplash Willie (Walter Matthau) — a legal scoundrel of the first order — arrives on the scene! For if Harry follows shyster Willie's advice and feigns a crippling injury, the two charlatans can split a cool million in phoney insurance claims. But can Willie's world-class finagling dispel those ominous words that lie within the fortune cookie on Harry's hospital plate: You can't fool all of the people all of the time?