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