John Thinnes, a detective on the Chicago police force, and Jack Caleb, a well-known psychiatrist, were friends - unlikely friends, maybe, with very different lives, but men who liked and respected each other. And they had one significant experience in common: Both had been "in country" in Vietnam during the war. Their "labels" were different - Thinnes had been in the military police, Caleb a medic, a conscientious objector who chose to fight with his medical equipment and his ability as a doctor as his weapons, whether his patients were wounded on the field of battle or on the crowded, dangerous streets of Saigon.

Arriving home, both men would have liked to forget the horrors of that war but could not banish them from their memory. They had left Vietnam, but Vietnam would never leave them. In the years since the war ended, Thinnes married and fathered a son, Caleb prospered with his psychiatric practice and found a gay lover. Later, a series of murders and rapes brought the police officer and the psychiatrist together in an oddly matched friendship, each contributing his special knowledge to try to solve crimes that were hard to unravel. But memories remain - ugly memories of maiming and killing on both sides, not only of soldiers but of innocent Vietnamese farmers and their families, of drug dealers and the city's poor. And now, on a morning shortly into the new millennium, Jack Caleb is listening to the radio and hears of the shooting death of a Vietnamese immigrant woman in Chicago's "Little Saigon," and a flashback leaves him trembling.

Thinnes's reaction to the murder is of a different kind. He had been assigned to the murder case, but when his lieutenant learns that Thinnes had known the dead woman in Saigon, had even attended her marriage to his now-dead buddy, he takes him off the case, leaving Thinnes's partner to use her outstanding talents as a detective under the officer who takes John Thinnes's place.