The Turtles and the Shredder battle once again, this time for the last cannister of the ooze that created the Turtles, which Shredder wants to create an army of new mutants.

While Al Capone works his way up from top-dog street gang thug captain in Chicago to U.S. crime king, his brother Jimmy Capone chooses the righteous way, actually with father's blessing, leaving Illinois for small town Harmony in Nebraska, where he adopts the alias Richard Hart, marries teacher Kathleen, has offspring and becomes its incorruptible town marshal, with a loyal Indian deputy. When his efficient fight against Al's illegal alcohol trade starts to bite financially, the gang's top lawyer is sent to buy 'Hart' or order his death, but recognizes Jimmy and arranges a fraternal reunion in Chicago. Yet money nor threats can turn Jimmy bad...

Stone (Peter Coyote) hits an armored truck without his usual driver. The ensuing getaway leads to the death of an innocent. The payback is swift and brutal. The wronged father hires a twisted, sociopathic assassin to avenge his loss. One by one the offenders are punished through grisly executions. Stone uses his wits to find a reclusive friend Terry (Mel Smith) just in time for a psychedelic funhouse showdown with his stalker.