Tampico plot
"Tampico, double-crossroads of the world !"
While sailing in the Gulf of Mexico, oil tanker Captain Bart Manson rescues the beautiful Katherine 'Kathie' Hall after her ship is torpedoed by a German submarine. Both fall in love and they get married. During one of the subsequent trips Bart's oil tanker sinks under suspicious circumstances. Kathie is, because of her unclear past, and on the directions of Bart's first mate Fred Adamson, seen as the prime suspect. But Bart is convinced of Kathie's innocence. He therefore investigates himself and has to deal with Adamson's true identity.