Aging mobster Big Mac (Donald MacBride) is looking to pull off one more heist before he retires. With his sights set on robbing a California casino, Big Mac breaks one of his former associates, Roy Earle (Humphrey Bogart), out of prison to mastermind the job. When the robbery goes awry, Earle is forced to go on the lam and settles for the night in the hills of the nearby Sierra Nevadas. But, with the cops on his tail, Earle is soon forced to fend off the law from the mountains.