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.

Sidney Poitier
as Virgil Tibbs

Barbara McNair
as Valerie Tibbs

Gerald S. O'Loughlin
as Jack Pecora

Sheree North
as Mrs. Morgan

Fred Beir
as Bob Alford

Allen Garfield
as Benjy

Bernie Hamilton
as Lt. Jessop

Graham Jarvis
as William Martin

Raúl Juliá
as Juan Mendoza

Ron O'Neal
as Joe Peralez