...that turns briefly into a noir thriller near the end, and takes place almost entirely on Christmas Eve. Of course the plot is manipulated to make time for a couple of songs, including Cole Porter's "Night and Day," when she has to pretend she's a night club singer during her investigation.
The film begins while her train is pulling into New York, and during a brief pause before continuing to Grand Central Station it pauses long enough for her to see a murder being committed in a warehouse window across the tracks. Naturally since she's been reading a murder mystery, so nobody believes she saw a real murder, so she tries to enlist the author of her book to help her solve the crime. Somehow she stumbles into the reading of the will for the dead man and is mistaken for his nightclub mistress, who is the sole heir. It's too bad Durbin did not continue her career, as she does a great job playing an adult role with a winning blend of comedy, drama, romance and still a bit of music.