Cock Robin is the swaggering ballyhoo man of a Hungarian sideshow known as the Palace of Illusions. The highlight of the show is a reenactment of Salome's dance of the seven veils, replete with the beheading of Jokanaan. The performer portraying Salome is in love with Cock Robin. Jealous, sinister The Greek is determined to eliminate that competition.
Lightnin' the dog and his master, Tom Harding are on to a group of smugglers who operate down at the harbor. Tom nearly bags them, but he's overwhelmed and they take flight. His girlfriend bluffs her way into the gang's hideout, but is discovered and held back. Tom is again overpowered by the crooks and thrown in a secret dungeon, but he fights his way out.
When Prince Danilo falls in love with American dancer Sally O'Hara, his uncle, King Nikita I of Monteblanco, forbids him to marry her because Sally is a commoner. Thinking she has been jilted by her prince, Sally marries wealthy Baron Sadoja. When the elderly man dies suddenly, Sally must be wooed all over again by Danilo.
During a carnival in Venice, Horace Pierpont, a wealthy American (Lewis Stone), falls in love with Fay Kennion (Virginia Valli). Their romance is derailed when she goes over to his apartment and finds the vampy Fifi (Nita Naldi) there. Fay goes down to Algiers, where she marries a former sweetheart, Dr. Alan Mortimer (Edward Earle).
Two cowboys drift into town. Both are broke, and one of them jokingly suggests they rob the local express office. A citizen overhears them, and when the office is robbed soon afterwards, the cowboys are blamed for it.
