Frankie loves Johnny, but he has another great love, gambling. Sometimes Frankie believes he loves gambling more than he does her. He has asked her to marry him but she refused saying she could never agree to marry him if he continues betting and gambling away all his money.
They earn their living together, as singers on a Mississippi gambling showboat owned by Clint Braden.
A gypsy fortune teller interests Johnny greatly. When she tells him that he could change his losing streak with a new redhead who is coming into his life, Johnny is impressed even more. The redhead turns Johnny has troubles on his mind out to be Braden's old flame-Nellie Bly. Frankie becomes very jealous of Nellie and at the same time Braden becomes jealous of Johnny even more so when Nellie uses Johnny to persuade Braden to marry her.
Johnny's piano-playing buddy, Cully, writes a song for them called "Frankie And Johnny". They sing this for the first time to the passengers on the Mississippi show boat. It proves a gigantic hit for them. And it looks as though Frankie and Johnny will finally go to Broadway after the Mardi Gras Week in New Orleans.
Just as the fortune-teller predicted, Johnny wins a large sum of money with Nellie beside him. Angrily, Frankie throws all the money away. Then Braden's dumb bodyguard, trying to help Braden win Nellie back from Johnny, puts a real bullet in the gun that Frankie uses to "kill" Johnny at the end of the title number on stage.
But, the lucky cricket that Johnny wears as one of his many lucky mascots saves his life. Frankie decides she loves Johnny no matter how much he gambles and all the problems are happily sorted out by the end of the film.
(Movie overview by Elvis Monthly - Issue 104, September 1968)