By John Altman

Putnam. 262 pp. $24.95

Ahigh-level al Qaeda operative named Ali Zattout has been captured in Pakistan and brought to a CIA safe house in Upstate New York for questioning. Dr. Louis Finney is brought in to supervise the interrogation. Finney is a bird-watcher and grieving widower who bitterly regrets his earlier work for the government, when "the Hippocratic Oath had been thrown cheerfully over the side by the doctors involved . . . wrapping themselves in the exalted cloak of national security as an excuse."

This sensitive soul would not seem the ideal candidate to guide a key interrogation in the war on terror, but no matter -- his troubled conscience is intended to be a key plot element as John Altman's novel unfolds.

Zattout is a sophisticated man who speaks excellent English and seems willing to cooperate, but the process is moving too slowly to suit the CIA and military officials. Finney favors winning the prisoner's trust, but others urge more aggressive options: "torment, or torture. The line between the two was kept purposely blurred." Pressed by CIA officials, Finney suggests a hard-line solution: "If coercive techniques fail . . . we might consider the implementation of a depatterning strategy. The subject is reduced to an essentially vegetable state, using electroconvulsive shock, sleep deprivation, sensory isolation. Once fully depatterned, he is unable to feed himself; he becomes incontinent; he is unable to state his name or the date. Then we begin to rebuild."

While Finney and CIA officials debate the carrot versus the stick, an assassin who calls himself Simon Christopher is plotting to penetrate the high-security safe house and kill Zattout. This is one strange assassin. He is a small, nondescript man ("his complexion was European, yet his features hinted at some other ancestry") who at one point studied at a "temple" under a "master" who called him "little mouse." He grieves for a teenage sweetheart he barely knew, he meditates a lot and, in the process of trying to get to Zattout, he kills a dozen or so people, including members of Zattout's terrorist cell, CIA agents, two teenagers and a pregnant woman, plus several dogs. He dresses in black, wields a wicked knife, and calls himself "a ghost wind," while a nervous CIA man thinks of him as "the dark magician."

All this makes him seem less a flesh-and-blood assassin than a bad dream, and his killings become more bizarre than scary. He concocts a highly improbable plan to penetrate the isolated CIA safe house, which is guarded by fences, Marines, dogs, electric sensors, cameras and the like. His plan, however fanciful, moves us inexorably toward his showdown with the combined forces of the Marines and the CIA.

Thrillers often place larger-than-life characters in over-the-top situations. This is the second of Altman's novels I've read that offers life-size characters in quasi-believable plots. His "A Game of Spies" featured two ordinary people attempting a spy mission during World War II; their heroism was touching. But "The Watchmen" is so understated it's barely there. Altman recalls in detail the notorious 1963 experiments whose subjects were willing to inflict painful electrical shocks on others when so ordered by authority figures. Apparently we're supposed to be caught up in Finney's moral drama as he decides whether "aggressive" techniques are justified against the alleged terrorist. At the outset, Finney argues, "We want to show him a way to cooperate that still lets him feel right about the choices he makes. As the interrogation progresses, we need to convince him that the values on which he's been raised are misguided. This involves gaining the subject's trust."

But Finney doesn't fight very hard, particularly after Zattout defies and insults him; uncovering sleeper cells pretty clearly justifies some nasty business. This isn't the Abu Ghraib prison, but when Finney learns that the prisoner is terrified of dogs, he considers the safe house's contingent of Doberman pinschers as a means of persuasion. For all his soul-searching, Finney ends the novel as muddled about the morality of torture as he was at the beginning. The other characters are no more exciting. One senior CIA agent has an annoying habit of recalling dumb jokes by Milton Berle, Red Buttons and Rodney Dangerfield when he should be fighting the war on terror, and a silly teenage girl who makes the mistake of flirting with the terrorist pays the price you might expect. Once the doctor's dilemma fizzles, we're left with the assassin, whose exploits are not believable enough to carry the story. There's a good and timely novel to be written about the conflict between determined interrogators and defiant terrorists, and about the morality of torture versus the demands of national security, but Altman hasn't written it.