In some of the books, notably Ten Days' Wonder (1948) and Cat of Many Tails (1949), Ellery's actions cause additional deaths, and his anguish over his presumption and intellectual arrogance (he refers to his 'first victim' in Ten Day's Wonder) gives these stories additional depth and lasting interest. This book concerning the strangulation murders of six people during a hot summer  in New York City, shows the amount of action, psychological insight, and social observation Queen brought to the puzzle mystery. While Ellery and his father try to discern the pattern behind the murders and identify the killer, sensational newspaper and radio coverage whips the public into a frenzy, vigilante groups rise up, and the city bursts into lethal riots. After an exhaustive police investigation and some bravura reasoning by Ellery, the police set a trap for the killer, but before Ellery realizes that they have captured the wrong person, more deaths occur. Ellery resolves to quit his "glorious career of [bumbling] masquerading as exact and omnipotent science," but a wise professor dissuades him, avowing that the "great and true lesson" the detective should learn from the story is, quoting from the Gospel of Mark, "There is one God; and there is none other but He."(Mystery Men by S.T.Karnick)

A departure for EQ: more of a manhunt than a mystery, although with a neat twist. There's that extraordinary sequence with Ellery and the psychiatrist. Michael E.Grost suspects that the use of the name Casilis is in tribute to Mollie Casilis in Craig Rice's It Takes a Thief (1943). Despite the fact that Lee felt that this was his best book it was not published as a serial in a magazine prior to publication.
TV-Movie (simplified): "Ellery Queen: Don't Look Behind You." Recently chosen by the Members of the Independent Mystery Booksellers Association's online discussion group as one of the 100 Favorite Mysteries of the Century.