The Lady Luck is a floating casino sailing up and down the Mississippi. Among the passengers are Clarence (the owner's cat), Bruce (the Captain's Alsatian) and two stowaways: a weasel called William and a skunk called Rico. A gang of crooks hold up the casino and escape with the jewellery and cash, but the four friends follow them. They meet a horse called Wyatt, and between them they manage to capture the crooks and recover the swag.