Crackerjack spy yarn about an ultra-deep Soviet agent trying to come in from the cold--and a big step up for Reiss, who's previously spun out only so-so thrillers (Flamingo, 1989; Saltmaker, 1988, etc.). Reiss opens in 1967, with a group of Smith Falls, Mass., schoolkids studying current events--only these kids are Russian, and their town, a training ground for spies that's a carbon copy of the real Smith Falls, sits in Siberia. Cut to 1991: One of the kids, known only as Ash, is now a Washington Post reporter--and, like his ex-classmates, is feeding information back to Moscow through the group's leader, David Kislak. But lately Kislak has inexplicably been asking for data about Third World trade; curious, Ash breaks the cardinal rule of no-contact. Kislak gives Ash a vague explanation and, when Ash leaves, sends a killer after the nosy spy--sparking the nonstop manhunt that dominates the story. Running fast, Ash tracks down another group member; but she, loyal to Kislak, tries to kill Ash--who then seeks refuge in the Soviet embassy in Washington, only to learn that no one there knows of his group: So many years have passed that the group's Moscow controls have died. Kislak, Ash realizes, is acting on his own, fattening his wallet by selling to various parties the data fed him by the group. Meanwhile, Gorbachev is ousted by the coup, and two KGB honchos--an old-liner and a moderate--begin to vie for control of Kislak's network. As Ash heads to the real-life Smith Falls to resolve matters by locating the group's founder, Kislak follows-- but the KGB moderate follows as well, cavalry riding to a last- minute rescue during a brutal, bloody climax. High-velocity action plus clever interludes--as when Ash confesses to his girlfriend that he's a spy--add up to a smart, taut thriller, Reiss's best by far.