A wrenching and lurid Matt Scudder outing that pits the unlicensed p.i. against childkilling slime and climaxes in vigilante violence. Perhaps the plot externals are so fierce here because Scudder's internal demons have mellowed: He seems to have won his battle with the bottle, and his loneliness has been banished by love for call-girl Elaine and by friendship with Irish gangster Mick Ballou. The only enemy left is the evil of others--which is waged war upon in two related cases here. In the first, Scudder is hired by a dying man (AIDS) to determine whether, as both he and the cops suspect, the robbery/rape/murder of the man's sister was really a setup by her greedy husband, cable-TV magnate Richard Thurman, to cash in on her life insurance. In the second, Scudder is asked by an A.A. colleague to watch a rented video of The Dirty Dozen; hidden on the tape is a snuff film in which a costumed man and woman torture, then kill, a teenage boy. In one of several coincidences that gear the plot (and which Block doesn't try to hide), Scudder, trailing Thurman, recognizes the man from the film--Bruno Stettner, who, with seductive wife Olga, had mesmerized Thurman into joining their sadistic sex games and killing Mrs. Thurman for profit. This Scudder learns by winning Thurman's confidence during several chats (which, added to his long talks with Ballou, Elaine, and a cop-pal, give the narrative a lazy, even slack, feel); but although Thurman's confession solves that case--and leads to his murder by the Stettners--it takes Scudder and Ballou's vengeance by cleaver and gun, in a grand guignol finale, to close out the second. Written with great heart and care, but even less of a mystery and more of a melodrama than A Ticket to the Boneyard (1990), and smacking a bit too much of Andrew Vachss (the child-abuse vigilantism), as if Scudder/Block were treading water, albeit it dark and deep.