A retired lady judge runs a private detective agency with a charming ex-con as her leg man and various parolees helping in the day-to-day operation.

A bumbling government employee accidentally destroys a small fortune and decides to break into the US Mint to replace it, but before long everyone wants a slice of the action - and the money.

African-American Philadelphia police detective Virgil Tibbs is arrested on suspicion of murder by Bill Gillespie, the racist police chief of tiny Sparta, Mississippi. After Tibbs proves not only his own innocence but that of another man, he joins forces with Gillespie to track down the real killer. Their investigation takes them through every social level of the town, with Tibbs making enemies as well as unlikely friends as he hunts for the truth.