The sweetly inconsequential Americanization of an inoffensive Russian specialist in chaos theory. In order to take the pulse of political measure in the USSR, Lemuel Falk has been applying annually for 23 years for an exit visa. When he finally gets one, he decides (why not?) to accept it and takes up a visiting post at the Institute for Advanced Interdisciplinary Chaos-Related Studies in Backwater (pop. 1290), New York. His early adventures in this brave new world are seasoned with mild multicultural humor (Falk's bewilderment about the meaning of ""girl Friday,"" his dream that American streets are paved with Sony Walkmans, an academic debate in which Falk's opponents charge that he's nothing but a randomist masquerading as a chaoticist). When Littell hunkers down to a plot, it's a sendup of the spy gambits he's offered in An Agent in Place, The Once and Future Spy, etc. Falk's stand (actually a lie) alongside his inventive young lover Rain Morgan in protest against a local nuclear waste disposal plant brings him to the attention of a laconic Oriental visitor, an importunate Syrian student, a pair of Las Vegas persuaders, his former Russian mistress, and the ubiquitous feds -- all of them convinced that his work on calculating pi to millions of decimal places has given him a key to the deciphering of all possible codes. On his days off -- which seem to be numerous -- Falk works, though not very convincingly, at cracking the case of a serial killer whose victims turn out to be anything but random. An international episode saddled with too much intrigue for its own good. Delicate stuff, all right, but lacking the resonance of Louis Jones's even more delicate Particles and Luck (1993).