Amazon.com description: Product Description: The Madagascar Corundum, a large heart-shaped ruby set in a brooch with emeralds and diamonds by an Italian Renaissance artist, has come into the hands of a prominent jeweler, Charles Kukorin, who bought it for three million dollars from the Emir of Madagascar, and is reselling it to a young Long Island millionaire for four. The millionaire, Henry Rubenstein, has asked that it be delivered to his Southhampton estate, and for this delicate task Charles Kukorin hires the off-beat John Shaddows, an ex-architect turned private detective, who has run this kind of errand for him before, and who tells the story in the first person.

The brooch is duly delivered. Claude Kukorin, the son of the jeweler, Charles, is a friend of Henry Rubenstein and a houseguest. The ruby is then locked in the family safe. John Shaddows is invited to stay for lunch at the Rubenstein mansion.

Among Henry Rubenstein's houseguests are: Stella Coverly, an aging and alcoholic movie queen; Dino Fuchietti, a Los Angeles hotel mogul; and Janet Johnson, a stunning young woman of loose morals and a friend of Claude Kukorin. After lunch, Shaddows goes to Janet Johnson's bedroom at her invitation, and things are proceeding along very satisfactory lines when three shots are heard. Shaddows runs downstairs and finds Henry Rubenstein dead, Claude Kukorin wounded, and the brooch missing. The ailing Claude tells Shaddows that the thieves were two Orientals and a seven-foot-tall black man.

Shaddows returns to New York to Charles Kukorin's apartment, where he meets, first, Amanda Brooks, Kukorin's publicity expert (she keeps his name out of the papers), who flirts with him and, second, Sharon Halliday, Kukorin's mistress, a television personality and health nut, who unsuccessfully tries to talk Kukorin out of hiring Shaddows to find the brooch, and find the murderer(s).

The suspect list, at this point, also includes Lady Carol Hampshire, a beautiful, somewhat fey expert on jewels, who has been working at Kurkorin's firm and who knew the worth, buyer and delivery date of the Madagascar Corundum. She has formed a passionate attachment to the jewel -- a heart-shaped ruby in the brooch. A visit to her elicits only the information that she sometimes dated Claude Kurkorin, and that she knew another suspect, Pierre Lufal, a lawyer active in the international gem trade. Later, Shaddows finds Lady Carol wandering around his darkened apartment in an apparent daze, and she seduces him.

Before the brooch was sent off to Rubenstein, Lufal had come to Charles Kurkorin with an offer from the Minister of Mines, Mr. Lawson-Johnston, of the Lower Nigeria. Kukorin turned down the offer, but Lufal and his client, Lawson-Johnston, both knew to whom the brooch had been sold and the time and place of delivery.

A visit by Shaddows to Lufal reveals he also represents Stella Coverly, the aging movie queen, in the sale and purchase of her jewels.

Shaddows leaves Lufal's offices and goes home; as he reaches for the light switch by the door, he is grabbed, picked up and thrown across the room, and beaten. On coming to in the early morning and while looking for the first aid kit on the top shelf of his closet, Shaddows finds a package. He opens it -- the ruby brooch! -- which he puts into his safe deposit box.

After Storm Johnson and Lawson-Johnston are also murdered, and after being kidnaped by a Japanese jewel fence, Shaddows resolves these very complicated matters -- and returns the Madagascar Corundum to the Estate of Henry Rubenstein.