After a group of young revolutionaries break into a company's corporate headquarters and steal $5,000,000 worth of heroin to keep it off the street, they call on San Francisco Police Lieutenant Virgil Tibbs for assistance. Tibbs is understandably reticent about helping the radicals, since they broke a number of laws (despite a good cause), but when the group is also accused of a murder it didn't commit, Tibbs decides to go along, but without the police department's knowledge.