Brooks Hansen, . . Farrar, Straus & Giroux, $24 (320pp) ISBN 978-0-374-27019-3

"Able was I ere I saw Elba" tends to be all most people recall about Napoleon Bonaparte's fate in exile. In this intriguing but disappointing novel, Hansen (The Chess Garden; Perlman's Ordeal) fleshes out a later stage of the failed conqueror's banishment. After a stint on Elba and his epic defeat at Waterloo, Napoleon is sent in 1815 to the tiny south Atlantic island of St. Helena, which is destined to be his final resting place. His arrival inspires trepidation among the natives, who view him as a white demon, but a teenage girl from a prominent family quickly becomes infatuated with the leader, who is known locally as Bony. The initial chapters are promising as Hansen brings his curious island setting to life and sets the stage for an unlikely May/December affair, but the failure of the lovers ever to come together is a major disappointment. Hansen pens some effective flirtation scenes, but wastes numerous chapters on a murky subplot involving Fernando Lopez, a 16th-century nobleman who was banished to St. Helena for becoming a Muslim and returns to haunt the island. The portrait of Napoleon is flawed, too. Though Hansen strives to chronicle the quirks and idiosyncrasies of the defeated conqueror, he barely scratches the surface of Napoleon's character, painting a picture of a decidedly mellow and rather listless man. The strength of the book is Hansen's lovely prose and his striking descriptions of the island and its inhabitants, which outshine the depictions of most of his human creations. Hansen's inexplicable failure to follow through on a promising conceit makes this novel a very ordinary work from a talented writer. (Jan.)