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.

Chasing down a serial killer who complicates his crimes by leaving behind evidence implicating innocent people, Lincoln Rhyme and Amelia Sachs reluctantly team up for the investigation only to find themselves rendered the killer's next targets.