In this wry sendup of tales discovery and darkest Africa ala Joseph Conrad, Albert Sanchez Pinol mixes adventure, invention and historical incident. Told as a kind of breathless, turn-of-the-century tale that would have been serialized in the popular press, Pinol's novel recounts the mind-boggling deprivations of Marcus Garvey, who emerged, two diamonds in hand, as the only survivor of a 1914 expedition into the Belgian Congo, manservant of Richard and William Craver, sons of the Duke of Craver. The plot is all too intricate and great fun.  (CAF44, $15.95)