Lawrence Sanders' best seller The First Deadly Sin gave Frank Sinatra his first starring movie role in a decade. His haunting work as a veteran cop at loose ends turned out to be his final performance. While his wife (Faye Dunaway) lies hospitalized near death, NYPD detective Edward X. Delaney (Sinatra) takes on a tough murder case. He's always gone by the book, but his present circumstances are wearing on him - and he might just bend the rules to nail the killer (David Dukes). Aided by a museum curator (Martin Gabel), a gruff coroner (James Whitmore) and a Victim's widow (Brenda Vaccaro), he orchestrates a meticulous manhunt. One mistake and the killer goes free. Delaney's plan must not fail.