Something seems fishy when a married man finds new adventure and romance in this comic fantasy. Arthur Peabody (William Powell) is a slightly stuffy businessman from Boston who after turning fifty finds himself suffering from a full-fledged midlife crisis. On the advice of his doctor, Peabody and his wife Polly (Irene Hervey) head to the Caribbean for a restful vacation. One evening, Peabody decides to do some fishing, and he pulls in a highly unexpected catch -- a beautiful mermaid named Lenore (Ann Blythe). Peabody takes the mysterious creature home with him (keeping her in a backyard pond for safekeeping), but while he soon becomes infatuated with Lenore, she's quite shy around others, refusing to let people see her except for the tip of her tail, so few believe his story about the big one he's reeled in. Makeup whiz Bud Westmore designed the special mermaid costuime for Ann Blythe; keep an ear open for the song "The Caribbees", co-written for the movie by Johnny Mercer.