It's been a while since we first met Lee Child's Jack Reacher in Killing Floor. Fifteen years and sixteen novels later, Reacher still lives off the grid, until trouble finds him, and then he does whatever it takes, much to the delight of readers and the dismay of villains. Now someone big is looking for him. Who? And why? Hunting Jack Reacher is a dangerous business, as FBI Special Agents Kim Otto and Carlos Gaspar are about to find out. Otto and Gaspar are by-the-book hunters who know when it's necessary to break the rules, but they Don't Know Jack. Reacher is a stone cold killer. Is he their friend or their enemy?