A Scotland Yard undercover detective is on the trail of a saboteur who is part of a plot to set off a bomb in London. But when the detective's cover is blown, the plot begins to unravel.

CAST: SYLVIA SIDNEY, OSKAR HOMOLKA, DESMOND TESTER, JOHN LODER, JOYCE BARBOUR,MATTHEW BOULTON, S.J. WARMINGTON, WILLIAM DEWHURST, PAMELA BEVAN, PETER BULL, ALBERT CHEVALIER, CLARE GREET, CHARLES HAWTREY, ALFRED HITCHCOCK, MARTITA HUNT, MIKE JOHNSON, HUBERT LESLIE, AUBREY MATHER, FREDERICK PIPER, FRED SCHWARTZ, TORIN THATCHER, AUSTIN TREVOR, JACK VYVYAN, SAM WILKINSON
DIRECTOR: ALFRED HITCHCOCK
DURATION: 76 MINS