DETECTIVE COMICS GOES ALL IN! A serial killer is stalking Gotham. But its victims are all juvenile delinquents, teens, and young adults with criminal records and time served. Are they even worth saving? For Batman, the answer is always yes. No matter who they are or what they've done, every life is worth preserving. Not everyone agrees with this sentiment, as Bruce Wayne will discover when an old family friend invites him to test a new longevity drug, Sangraal, something only the very rich will ever have access to. What's Sangraal's connection to these strange murders, and what's the price of immortality? Find out in the critically acclaimed story The Mercy of the Father by dynamic duo Tom Taylor (Nightwing, Superman: Son of Kal-El) and Mikel Janin (Batman and JSA)! Collects DETECTIVE COMICS issues #1090-1096.