In a story based on fact, Lancaster plays surly, withdrawn inmate Robert Stroud, sentenced to life in prison, who cures a sick bird which flies into his cell one day, and later becomes an internationally recognized ornithologist. Fighting against an overly protective mother (Ritter) and a
truculent warden (Malden), Stroud is nonetheless able to continue his research even when sent to Alcatraz, the notorious "Rock" in San Francisco Bay, home to only the most incorrigible prisoners. Finally, though, after an abortive romance (Field) and a prison riot which he helps quell, Stroud is
able to tell his remarkable story to writer Tom Gaddis (O'Brien, playing the author of...