Unnatural Causes

After an interesting premise and smooth beginning, this medical thriller sinks beneath an unbelievable plot, cardboard characters, clumsy writing and one of the most annoying love stories in years. Ex-Navy SEAL commando Brian Thorpe, ace surgeon at Bethesda Naval Hospital, teams up with Diana Keegan, of the Epidemic Intelligence Service of Atlanta's Center for Disease Control, to find out why small capsules are being discovered inside the bodies of certain Vietnam vets who are dying in what appear to be random accidents. Brian and Diana crisscross the country, dogged by shadowy Russian and U.S. agents, before uncovering a germ warfare scheme begun 15 years earlier in Vietnam. Murder attempts don't stop them but treachery almost does. A plethora of medical detail is interspersed with a great deal of running around and much discussion (often in bed) of the pros and cons of the Vietnam WarDiana was a ""radical'' while Brian was in the thick of battle. The pat, unlikely ending is bad enough, but what really ruins the book is the love story of two large children too boring to merit all this attention. Olshaker wrote Einstein's Brain. (September 30)