With An Agent in Place, Robert Littell proves once again that he is a master storyteller in the ranks of John le Carre, Len Deighton, and Graham Greene. Deep in the vastness of the Pentagon and the bowels of the massive KGB center in Moscow are old Cold Warriors who refuse to fade away. Yet how can they wage their battles when there are no enemies anymore? Their answer is Ben Bassett. Sent to Moscow as a lowly embassy ''housekeeper,'' Bassett meets a fiercely independent, passionate Russian poet, Aida Zavaskaya, and falls under her spell. Together they become pawns in a dreadful game that leads to the clandestine heart of the Soviet system itself.