You know you’re dealing with the youngest inheritor of the Golden Age tradition of Agatha Christie and John Dickson Carr when the story is preceded by a floor plan—in this case, the second floor of Calvert Manor, the Washington home of the late Andrew Shepherd. After languishing on the market for months, Calvert Manor has attracted some serious attention not only from a friend-of-a-friend of State Department pensioner Richard Michaelson (Worst Case Scenario, 1996, etc.), but from politically-connected realtor Avery Phillips, whose story about the European Union’s interest in more office space doesn’t hold water for a minute. While Michaelson is still digging among the skeletons in the closets of the Shepherd family and the CIA, the mystery blossoms into his favorite kind of homicide: the impossible kind that leaves every suspect with an alibi and the killer with no apparent way to have entered or left the murder room. The suspects—bad-girl Cindy Shepherd, her better-behaved sister Catherine, Cindy’s rocker boyfriend, and the estate’s colorless trustee—are no more than a collection of tics and well-documented neuroses, but the political hanky-panky, which ranges from naughty Aldrich Ames to a secret 200 years old, is delightful. Readers who can swallow a deliriously artificial setup and a solution so recondite that the author ends with an offer to sell you a videotape documenting its operation will find this the cleverest whodunit of the season, wrapped up in the cleverest dialogue.