Scat Sweeney and Hot Lips Barton, two out of work musicians, stow away onboard a ship bound for Rio, after accidentally setting fire to the big top of a circus. They then get mixed up with a potential suicide Lucia, who first thanks them, then unexpectedly turns them over to the ship's captain. When they find out that she has been hypnotized, to go through a marriage of convenience, when the ship reaches Rio, the boys turn up at the ceremony, in order to stop the wedding, and to help catch the crooks.