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...

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. Meanwhile Splinter is coming... to a decision.

After thieves botch an armored truck robbery that leads to the death of an innocent young girl, her father vows revenge by recruiting a sociopathic hitman to track them down and assassinate them.