The sixth and final film in MGM's Thin Man series, starring William Powell and Myrna Loy as Nick and Nora Charles, characters created by Dashiell Hammett.

Phillip Reed, Keenan Wynn, Gloria Grahame, and Jayne Meadows are featured in this story set in the world of nightclub musicians.

A charity benefit sponsored by David Thayar is staged aboard the S.S. Fortune, Phil Brant's gambling ship.

The entertainment is provided by a jazz band led by Tommy Drake and featuring singer Fran Page and talented but unstable clarinetist Buddy Hollis.

The next morning, they show up at Nick and Nora Charles's apartment, having learned that Brant is the prime suspect in the murder.

Sneaking aboard the Fortune, Nick discovers on the back of a sheet of music a receipt signed by Amboy acknowledging that Drake's debt had been paid.

Nick gathers all the suspects by arranging a party on the reopened Fortune and announces that Buddy has fully recovered and that he will reveal the murderer's identity that night.

The script was one of three not written by the husband and wife team of Albert Hackett and Frances Goodrich, who had worked with Dashiell Hammett to develop the Nick and Nora characters earlier in the series.