A teenager at Rushmore Academy falls for a much older teacher and befriends a middle-aged industrialist. Later, he finds out that his love interest and his friend are having an affair, which prompts him to begin a vendetta.
With a plan to exact revenge on a legendary shark that killed his partner, oceanographer Steve Zissou (Bill Murray) rallies a crew that includes his estranged wife, a journalist, and a man who may or may not be his son.