The most delightful aspect of You Never Can Tell is the film's ability to successfully sustain its single joke for 78 minutes. The story begins when King, a German shepherd, falls heir to a fortune. Ellen Hathaway (Peggy Dow), trustee of King's estate, spends most of her time fending off would-be fortune hunters -- with the exception of personable Perry Collins (Charles Drake), who claims to have been King's "commander" in the wartime K-9 corps. Soon afterward, King dies of strychnine poisoning, and though no evidence exists, Ellen is held responsible. The film then shifts to the celestial way-station for animals known as "Beastatory." Here, the ghost of King implores a heavenly jury to be given an opportunity to return to earth and expose his genuine murderer. King gets his wish, and in a twinkling he is reincarnated in the form of private-eye Rex Shepard (Dick Powell). Shepard's girl Friday is Goldie (Joyce Holden), a reincarnated racehorse who insists upon outrunning buses just for the exercise. In his new human form, Rex returns to his mansion, where despite his animal instincts he can't help falling in love with Ellen as he endeavors to clear her name. To reveal more would rob the viewer of thoroughly enjoying this captivating piece of whimsy.