Ellery Queen had already appeared in several movies by the time this B-movie series kicked off. The novel THE DOOR BETWEEN was the basis, though radically rewritten, slight comedy the word in films of the type during this period. So altered that a novelization(neither of the cousins were involved) was written and published, then later reissued as The Vanishing Corpse. Ellery(Ralph Bellamy) is a slightly smitten man with Nikki Porter(Margaret Lindsay), a would be mystery writer he meets. And who became his assistant throughout the series, another trope of this genre of mystery/comedy at the time.
The murder victim is John Braun, a health business magnate, has always prided himself on his health. Now his personal, and the business, doctor, James Rogers(Michael Whalen) has told him that he’s dying of a mysterious illness. He wants to shut down everything, something the business partners object to. They’d been promised a piece in his will. He changes his will, leaving everything to his wife. Things are complicated because he’s mad with his daughter, Barbara(Marsha Hunt), who announced she would marry Dr. Rogers. When dad objected, she storms out and has been missing for several months.
Braun’s wife, and Barbara’s mother, goes to Inspector Richard Queen(Charley Grapewin) and wants her daughter found. Ellery , looking for new ideas for his next book, is listening in in Sgt. Velie’s(James Burke) office gets the jump and traces her, by following the doctor to the apartment of Nikki Porter, Barbara’s friend where shee’d been living.
Posing as a private eye, no name given, Ellery is hoodwinked into believing Nikki is Barbara and delivers her to the Braun estate, where she gets locked into the master’s suite of rooms, only to find him later in the bedroom with his throat cut. A locked room mystery, the only way out seems to be through Nikki. The probable murder weapon, a jeweled dagger/letter opener is missing. As well as the new will.
There’s quite a bit of comedy as Ellery hides Nikki in the home shared with his father. Not to mention the ending when he asks the would-be mystery writer to be hi secretary.
Entertaining little film.