The sons of a Chicago fireman who gave his life in the performance of his duties, firefighting brothers Kurt Russell and William Baldwin carry their lifelong sibling rivalry into their work. Russell is convinced that Baldwin hasn't got what it takes to remain in the fire department.
Baldwin is transferred to a safe assignment, assisting arson investigator Robert DeNiro, who is trying to make sense of a series of fires involving an oxygen-induced ball of fire called a backdraft. The investigation reveals a link between corrupt alderman J. T. Walsh and imprisoned pyromaniac Donald Sutherland.
The trail of evidence leads Baldwin to suspect that his brother Russell, a much-decorated hero, may be the inside man setting up the arsons.