 A prisoner at a federal prison in Colorado is killed. Dying, he tells the warden that a break-out is about to be attempted. Because the prison houses some of the worst criminals in U.S. custody, the FBI is called into the case. Erskine goes undercover as a prisoner and is the new cell mate of Fritz Moline, a cunning criminal suspected of organizing the escape. But Moline, after planning the escape for five years, may kill Erskine first.