Marty Allen, veteran news reporter, is given the most challenging assignment of his career: determine if iconic movie actress Marilyn Monroe machine-gunned down seven bikers in 1961. At the same time, he wants to know why his girlfriend, a hard-nosed police detective, left him for a cop who abuses women and breaks legs, a quest that will nearly cost him his life. According to a tipster, the bikers almost assaulted Monroe while she was strolling along the beach in Hollywood, Florida. But four mafia soldiers, secretly providing her protection at the behest of their boss, rescued her. They were about to blow away the would-be attackers in a warehouse - until Monroe, seeking retaliation, asked to do the honors. Lending a modicum of credibility to this account, the tipster asserts that it happened shortly after Monroe was released from a psychiatric hospital. Marty, who works for a news and entertainment magazine, doesn't buy any of it initially. Yet he digs deep to learn about Monroe's difficult life and her controversial death at a young age. He discovers her alleged incident is remarkably similar to the St. Valentine's Day Massacre, where mobsters blasted away seven men in a Chicago garage in the 1920s. He examines Monroe's ties to a mafia kingpin. And he even tracks down the Tommy Gun she supposedly used and verifies it's the same model involved in the earlier Chicago mob hit. Ultimately, Marty will find the shocking truth behind the tipster's claim the actress was a mass murdererer.