Detective Jack Hale investigates the deaths of seemingly healthy young women and the trail leads him to a professor's laboratory. A professor who feels scorned starts to use paralyzing spiders on young women who remind him of his ex-wife.
Hale learns that Lyford (from his previous case) wasn't his real partner, but rather a test to see if he is ready for this sort of field work. Carter, his real partner, and Hale team up to try and stop a criminal taking body parts from organ donor recipients.
When the pedophile attached to an abduction winds up murdered, Hale and Carter suspect that a vigilante is at work.
Hale, Carter and Cavanaugh try to find the killer responsible for murdering twins and the clues point to another set of twins.
Even as Jack tries to convey to Danielle what entails a deviant crime, they discover a dead body, shaved and naked, with a living snake inside it. The investigation reveals that a killer is following the rites of the Egyptian book of the dead.
Hale has to deal with family issues when a copycat murderer uses the M.O. of Hale's serial killer father.
Carter, Hale and Cavanaugh trail a series of murders that mimic events from video games.
Detectives Hale and Carter try to piece together a murder spree from the memory of a victim who escaped a fate of death.
Hale and Carter try to piece together clues when murders coincide with earthquake epicenters.