Sam Fuller's explosive pulp classic, a red-menace thriller, pitched near hysteria from start to finish. Richard Widmark's lone-wolf pickpocket winds up caught between the Feds and the Reds when he unwittingly lifts stolen microfilm from Jean Peters, a hooker being used as a courier by a Soviet spy ring. Thelma Ritter's loveable stool-pigeon suffers one of the great movie deaths. Definitive Fuller, definitive noir.