The ""fourth Durango"" is the one in California--a tiny town that stays solvent by offering sanctuary to well-heeled fugitives from hired killers or mob assassins. And veteran Thomas' new novel, a violent yet wryly off-hand thriller, pits Durango's latest guest against a ruthless, elusive terminator. The newcomer in search of a hide-out is ex-Judge and ex-con Jack Adair, just out of jail (for tax evasion) but much better known for his alleged role in a bribery scandal involving an overturned guilty-of-murder verdict. Adair was in fact innocent, however: somebody was trying to frame him. Who and why? Adair doesn't know. But it soon becomes clear that this same somebody is now determined to kill the ex-judge. So Adair and son-in-law Kelly Vines (a disbarred lawyer) hide out in Durango, paying his bucks to the town's shrewd mayor, B.D. Huckins, and her lover/cohort, eccentric police chief Sid Fork. Huckins and Fork also agree to help Adair and Vines in a scheme to smoke out and trap the killer (the master of disguise who has already begun murdering Durango-ites, for not-very-plausible reasons). Eventually, however, Adair and Vines begin to suspect that one of their Durango hosts is in nasty cahoots with the psychoslayer. . .as the mayhem--including the kidnap of Adair's mental-patient daughter--escalates. The simple, vaguely familiar plot here doesn't have the intricacy or cleverness of vintage Ross Thomas (let alone the emotional weight of Elmore Leonard's Killshot). None of the roguishly likable characters has the rich charm and zest of such outstanding originals as Artie Woo (Chinaman's Chance, Out on the Rim). Still, though second-string Thomas, this is black-comic suspense that rolls along--on tart dialogue, tactile atmosphere, and choice narration--with easy authority.