Suave singer Scat Sweeney (Bing Crosby) and his partner, Hot Lips Barton (Bob Hope), stow away on a ship leaving New Orleans for Rio de Janeiro. On board, Scat falls for the beautiful and wealthy Lucia Maria (Dorothy Lamour), whose guardian (Gale Sondergaard) is hypnotizing her into consenting to an arranged marriage to the scoundrel Sherman Mallory (George Meeker). In Rio, the trio pose as a Brazilian song-and-dance act in an attempt to outwit Lucia Maria's predators.