Lawrence Block 
Hope to Die 

The city caught its collective breath when upscale couple Byrne and Susan Hollander were slaughtered in a brutal home invasion. Now, a few days later, the killers themselves have turned up dead behind the locked door of a Brooklyn hellhole – one apparently slain by his partner in crime who then took his own life.There’s something drawing Matthew Scudder to this case that the cops have quickly and eagerly closed: a nagging suspicion that a third man is involved, a cold, diabolical puppet master who manipulates his two accomplices, then cuts their strings when he’s done with them. No one but Scudder even suspects he exists. And his worst fear is that the guy is just getting started …