A Walk Among the Tombstones by Lawrence Block

"One million dollars cash, or we kill your wife". High-volume dope dealers make an easy mark for kidnappers. After all, what are they going to do, call the cops? But Kenan Khoury, heroin wholesaler to the five boroughs, haggled over the price, and his wife came back in pieces. The only person he can trust to avenge her is Matt Scudder, ex-cop, sober alcoholic, who wields his own brand of guerrilla justice. Scudder enlists his call-girl girlfriend Elaine, a streetwise punk from Times Square, and two phone-phreak computer geniuses to track the killers through the backstreets of Brooklyn. But the killers' depravity is matched only by their cleverness, and their next target is a little girl. In one of Block's most electrifying denouements, Scudder turns a cold trail into a red-hot explosion one rainy night in a Brooklyn cemetery. Crackling with the city's energy, A Walk Among the Tombstones weds the breakneck suspense of A Ticket to the Boneyard to the relentless moral vision of A Dance at the Slaughterhouse. It is Lawrence Block's finest, most deeply satisfying novel, and a virtuoso performance.