A husband and wife detective team takes on the search for a missing inventor and almost get killed for their efforts.

A Swedish princess boards an ocean liner in Europe en route to an acting career in America and finds herself getting inconveniently attached to a bandleader returning home. To complicate matters, a blackmailer on board apparently knows she is not who she claims to be - and he has his sights set on other passengers with secrets of their own. In the meantime an escaped killer has stowed away under someone else's identity, and is killing again to cover his tracks; five international police detectives on board are heading the investigation to find him. When evidence points to the princess and bandleader, they must find the killer themselves - before he finds them.

A grocery clerk, longing to become a cowboy actor, goes to Hollywood in search of fame and fortune. Unfortunately, his acting ability is non-existent.

A successful ex-boxer opens a high-class speakeasy in what once was the childhood home of a formerly rich society girl.

Singer Rose Carlton, otherwise known as 'The San Francisco Doll', accidentally kills her controlling boyfriend when he tries to prevent her from leaving. To evade the police, Rose sets sail for Nome with captain Bull Bracket. When the ship takes on another passenger, reformer Annie Alden, Carlton's life is changed forever, and she sets out to honor a deeply personal debt.

In the waning days of WWI, a U.S. "Mystery Ship," sets sail for the coast of Spain towing a submarine. Their mission is to find and sink a U-boat that has been especially effective in attacking Allied shipping. Posing as a harmless schooner, the mystery ship is in fact fitted with a formidable gun capable of sinking a U-boat. Stopping in the Canary Islands to refuel, the crew interacts with locals involved with Germans, and with Germans themselves, including the sister of the U-Boat commander, who is lurking offshore waiting for the coming battle.