When a murder desecrates the somber, book-lined halls of New York City’s iconic 42nd Street Library, Raymond Ambler, the library’s curator of crime fiction, has a personal interest in solving the crime. His quest to solve the murder is complicated by personal entanglements involving his friend—or perhaps more-than-friend—Adele Morgan. Not only does Adele’s relationship with the young woman staffer who was murdered get in the way of Ambler’s investigation, more disturbing for him is Adele’s growing interest in a darkly handsome Islamic scholar. Soon the Intelligence Division of the New York Police Department takes over the case from NYPD homicide detective Mike Cosgrove, Ambler’s friend and sometimes partner-in-crime solving. Ambler suspects that the murder of the young woman, who’d been working at the library under an assumed name and the curious intervention of NYPD’s intelligence division are connected. The trail of intrigue leads to a seemingly unrelated murder in an upstate prison and a long ago murder of a trade union reformer. No one else sees the connections Ambler is sure are there—not an unusual state of affairs for Ambler. But with the city’s law enforcement establishment determined to stop his investigation, the inquisitive and intrepid librarian faces challenges that may put his very life at risk.