The famous sleuth comes out of retirement to help his father hunt down a New York City serial killer: “Marvelous . . . one of his best” (Classic Mysteries).   In the dog days of August, it is no surprise to see New Yorkers perspire. But this summer, a killer called the Cat gives the city a new reason to sweat. He selects his victims seemingly at random and strangles them, then escapes without leaving a clue. As the death toll climbs, and the press whips the public into horrified frenzy, Gotham teeters on the edge of anarchy.   Ellery Queen, the brilliant amateur sleuth, has gone into retirement when the Cat begins to kill. As his father, a seasoned homicide detective, leads the investigation into the murder, Ellery tries to avoid getting involved. But as the body count rises, he can no longer resist the urge to hunt. The Queens are known for their curiosity—and everyone knows how curiosity can affect a cat.