Combining Russian detectives, Iranian spies, Vietnamese drug smugglers and a grief-stricken American hero, Thomas (Firefox) comes up a winner with his 13th novel. With his usual clarity and energy, he sets two plot lines in motion in the opening scenes: in Russia, local police discover the corpse of an American employee of Grainger-Turgenev, a joint venture in Siberia; in America, Billy Grainger of Grainger Technologies and his wife, Beth, are murdered in their home. Although the American deaths look like the work of robbers, Beth's grieving brother, ex-CIA agent John Lock, soon discovers that Grainger's profits, and Billy's lifestyle, are due to a heroin-smuggling ring that dates back to Billy's service as a CIA agent in Vietnam. Back in Russia, the local cops doggedly uncover evidence that Grainger-Turgenev is involved in a unique kind of drug-smuggling operation. As the Russian cops stir up enough waves to make themselves the target of retaliation by the smugglers and their allies in the Russian intelligence services, Lock must survive long enough to journey to Siberia, join forces with the police and avenge the death of his sister. Readers may be way ahead of Lock in figuring out the identity of the chief villain, but this lapse is more than made up for by Thomas's skill in mixing the grittiness of a police procedural with the high-concept tension of a spy thriller, and by the novel's exciting final third, a brilliantly executed chase sequence set in a Siberian blizzard.