"Amelia Sachs is hot on the trail of a killer. She's chasing him through a department store in Brooklyn when an escalator malfunctions. The stairs give way, with one man horribly mangled by the gears. Sachs is forced to let her quarry escape as she jumps in to try to help save the victim. She and famed forensic detective Lincoln Rhyme soon learn, however, that the incident may not be an accident at all, but the first in a series of intentional attacks....

Quadriplegic forensic criminologist Lincoln Rhyme leads his team--NYPD detective Amelia Sachs, officer Ron Pulaski, and FBI agent Fred Dellray--to find and stop a killer who uses electricity as modus operandi. Meanwhile, Rhyme is consulting on another high-profile investigation in Mexico with a most coveted quarry in his crosshairs: the hired killer known as the Watchmaker, one of the few criminals to have eluded Rhyme's net.

Lincoln Rhyme and Amelia Sachs are pitched against a Watchmaker, who plans his carnage with the precision of a timepiece.