Henry Boyle is a NYPD detective investigating a serial killer terrorizing Grand Central Terminal. Four murders arise in the course of a day and his investigative skills are stretched to the limit, far beyond the scope of his knowledge. Little does he know that the case would force him into its heart of darkness.

On the job for several days without sleep, Boyle, a case cracking insomniac, proved his sleep deprivation did not matter. He was the undisputed champion of closing cases, and he was almost sleep walking, when he was called to Grand Central Terminal to investigate a hanging from the fifth floor catwalk. As the kill count rises, notes of increasing desperation are uncovered that pull him into his own tormented nightmare.

Boyle had to do the thing he never could-trust the killer of four murders. The notes left with each victim are addressed to him stating, ” I know who the real killer is and we should team up to go after him.” But with each murder Boyle strains to uncover evidence, refusing to believe such a persistent call from a psychopathic lunatic. He puts his life in peril, because his reputation and job are at stake. Finally, the suspect traps him, and convinces him he is not responsible for the killing, and he wants to set the record straight. Putting aside the first rule of being a detective-never trust the suspect-Boyle teams up with him to search for this dangerous killer.