The Mystery of the Double Cross

Peter Hale (Leon Bary) is returning to America from overseas via steamship to receive his inheritance. On board, he receives a telegram warning him to beware the Double Cross. He doesn't know what it means, until he becomes enamored of a mysterious woman occupying cabin no.7. When a submarine is sighted, there is panic on shipboard. Peter and the mysterious woman are thrown together, and in the ensuing action, he sees a double cross symbol on her right arm, just below the shoulder... (official distributor synopsis)