After getting a wrongfully convicted man out of prison, defense attorney Mickey Haller is inundated with pleas from incarcerated people claiming innocence. He enlists his half-brother, retired LAPD Detective Harry Bosch, to weed through the letters, knowing most claims will be false. Bosch pulls a needle from the haystack: a woman in prison for killing her husband, a sheriff’s deputy, but who still maintains her innocence. Bosch reviews the case and sees elements that don’t add up, and a sheriff’s department intent on bringing quick justice in the killing of one of its own. The path for both lawyer and investigator is fraught with danger from those who don’t want the case reopened and will stop at nothing to keep the Haller-Bosch dream team from finding the truth.