A classic British spy mystery, and one of Hitchcock's best, THE 39 STEPS is the story of an innocent man who struggles to prove his innocence. Robert Donat gets more than he bargained for when he brings home a mysterious woman (Lucie Mannheim) who confesses to be a British agent on the hot trail of a dangerous spy ring. The woman is killed in Donat's apartment and he immediately finds himself on the run, burdened with the charge for her murder and the dangerous knowledge of her mission. The film is distinguished by its pioneering use of contrapuntal sound effects, as well as the dynamism between Donat and his costar Madeleine Carroll.