A Thames River barge operator finds a mysterious package dropped by smugglers.
Richard Arlen
John 'Captain' Martin
Greta Gynt
Peggy Mason
Donald Houston
Michael Mallard
Edwin Richfield
Daller
Michael Balfour
Bennett, short henchman
Arnold Adrian
Mark, tall henchman
Mary Germaine
Margaret Lane
Sydney Bromley
Enson
Vincent Ball
Williams
Elspet Gray
June Mallard
Antony Viccars
Detective-Inspector Hunt
Howard Lang
Marne
Montgomery Tully
Director
Charles Deane
Writer
