Lee Child's latest unputdownable thriller starring Jack Reacher features a chilling serial killer.Sergeant Amy Callan and Lieutenant Caroline Cook have a lot in common. Both were army high-flyers.Both were acquainted with Jack Reacher.Both were forced to resign from the service. Now they're both dead.Both were found in their own home, naked, in a bath full of paint.Both apparent victims of an army man.A loner, a smart guy with a score to settle, a ruthless vigilante.A man just like Jack Reacher.