- Cadmus Cole, mult-millionaire
- Margo Cole, a.k.a. Ann Strange, his niece
- Kerrie Shawn, his niece
- Edmund De Carlos, Cadmus' agent/assistant
- Lloyd Goossens, Cadmus' attorney
- Violet Day, Kerrie's roommate
- Beau Rummel, private investigator
- Ellery Queen, private investigator
Locale: New York City and Tarrytown, NY
Synopsis: Ellery Queen has gone into the P.I. business with Beau Rummel. Their first client is Cadmus Cole, multi-millionaire. Cadmus insists on hiring Ellery only. He provides a $15k retainer against future services, to be outlined in his will when he dies. His death occurs a few days later, on his yacht in the Caribbean, and he is quickly buried at sea.
The instructions he left are simple: Just locate his heirs for the estate. They are Margo Cole, the daughter of his brother Huntley (deceased); and Kerrie Shawn, the daughter of his sister Monica (also deceased).
Beau is going to run down the heirs, but as the contract was with Ellery only, he goes by Ellery's name to do so - a bit unethical.
The two nieces are found. Kerrie is looking for work in Hollywood, and Margo is living a life of opulent ease in Paris. They come to New York City. Now for the second stipulation in Cole's will: the girls will inherit his fortune, but only if they reside in his Tarrytown estate for a period of one year. They move in, but don't get along. If one of them dies, her share of the fortune reverts to the other. There are several attempts on Kerrie's life - are they accidents, or is Margo trying to cash in? Beau Rummel (as Ellery Queen) hatches a plan to protect Kerrie - by marrying her, which cuts her out of the estate. They wind up together in a cheap hotel room - then Margo is shot dead, with Kellie found holding the gun.
Review: This is a nice tight Queen mystery. There is a small cast of characters, and forcing the two heirs to live together adds to the tension. There are a number of odd clues and red herrings: false teeth, pens and pencils, wigs, etc. The will with odd conditions, and the fact that Cadmus Cole dies right away but is buried at sea (thus, no body) raises suspicion of hanky-panky. There's a lot of identity misdirection. A good solid Queen for the period.
One loose end: what happened to the injured horse?