This mafia movie, set in the world of saltwater fish, is the story of what happens when the son of the shark boss (De Niro) of a fish crime family is killed by a dropped anchor, and a bottom-feeder named Oscar (Smith) is found at the scene of the crime. Hoping to win favor with the enemies of the ganglord, the fast-talking hustler poses as the killer known as the “sharkslayer”, but soon learns it’s a dangerous game in a world where the big fish generally eat the little fish.

The sea underworld is shaken up when the son of the shark mob boss is found dead and a young fish named Oscar is found at the scene. Being a bottom feeder, Oscar takes advantage of the situation and makes himself look like he killed the finned mobster. Oscar soon comes to realize that his claim may have serious consequences.