Just about everybody knows John Sandford for his long and successful Prey series. But just as well written and maybe more fun are his Kidd books, of which this is the fourth. Kidd is a professional thief for the Internet age: a cyberprowler, a hacker extraordinaire. In The Hanged Man's Song, he gets word that one of his key contacts--a superhacker known only as Bobby, whom Kidd has never met but has relied on many times--has disappeared. Kidd and an old buddy, both of whom could be compromised by data in Bobby's files, go looking for him. Finding his brutally murdered body draws them into a Hitchcock-esque intrigue that eventually involves stolen government secrets, crooked politicians, and a rogue CIA agent who's as crafty as he is creepy. While filling his tale with fascinating and authentic-sounding lore about the hacker subculture, identity theft, and security cracking, Sandford keeps the action brisk with plenty of white-knuckle chases, tense stakeouts, and hairsbreadth escapes. Couple that with a smart, agreeable narrator and a cast of vivid characters evoked with an old pro's ease, and you've got one winning thriller. --Nicholas H. Allison