A woman awakes in the morning to find that someone has picked her apartment's apparently impregnable door lock and, terrifyingly, rearranged personal items, even sitting beside her while she slept. The intrusion, the police learn, is a message to the entire city of carnage and death to come. Lincoln Rhyme and Amelia Sachs are brought in to investigate and soon learn that the brilliant, sociopathic intruder, who calls himself the Locksmith, can break through any lock or security system ever devised. With more victims on the horizon, Rhyme, Sachs and their stable of associates have to try to follow the evidence to the man's lair... and discover what his true mission might be. Their hunt for the Locksmith is interrupted when an internal investigation in the police force uncovers what seems to be a crucial mistake in one of Rhyme's previous cases. He's fired as a consultant for the NYPD and confronts the hard choice of risking jail by investigating the Locksmith case in secret.
