Michael Pretorius, who appeared in Durham's Stealth (1989), leaves his considerable creature comforts to sort out the unlikely suicide of an old friend in Vienna where Russo-Japanese complexities teem. What does it take to pry a retired but still youthful American Defense Intelligence Agency operative from his vintage Jaguar, vintage Norton motorcycle, Devonian cottage, restauranteuse girlfriend, and loyal bull terrier? It takes only a note from the mother of an old Yale chum, Phillip Mathieson, in which she states that she doesn't think her son was the type to end his CIA career with a six-story plunge to the pavement. Could Pretorius take a little time to look into this as a favor to a grieving mother? Before you can say SST, Pretorius has flown to Mrs. Mathieson's bugged Park Avenue flat to get the details and then on to Virginia to begin picking the brains of his old spook chums. Concurrent with the suicide and the flying and the brain- picking is the discovery that the more-divided-than-ever Russians are acting especially Russian again, activating their extensive network of deeply buried bomb-shelters as if they were expecting some sort of nuclear holocaust before too awfully long. And while the Russians are digging, the Japanesewho hold the mortgage on both the Russians and the Americansare spying on the Russian digging (and the American interpretation of the digging), and Pretorius begins to see that his late friend was fatally interested in all of the aboveall of which seems to be coming to a head rather quickly. Agreeable thriller with a lot of good food but not as much tension as one might expector wish forfrom three irritable superpowers.