The people in Richard Wiley's fiction live in the dangerous territory where cultures and worlds collide. In Soldiers in Hiding, for which Richard Wiley won the PEN/Faulkner Award for Best American Fiction in 1987, the protagonist was Teddy Maki, a Japanese-American whose jazz band was playing in Tokyo at the moment Japan attacked Pearl Harbor. Now, in his new novel, Ahmed's Revenge, Wiley introduces us to Nora Grant, a young coffee farmer living in Kenya in the 1970s, a woman whose predicament is less obvious than Maki's but no less dangerous.         Nora has disbelievingly stumbled upon her husband, Julius, engaged in what appears to be ivory smuggling, one of the Europeans' dirtiest games. Before Nora can confront Julius, he is killed in accidental circumstances that soon look more like murder. Nora investigates her husband's affairs, coming across a        succession of people whose lives intertwine and intersect: her own father, living out his    retirement in England in apparent innocence; Mr Smith, who might be a murderer; Mr N'Chele, who might be a smuggler; Miro, the opera singer; Detective Mubia, a policeman of         divided loyalties--and Ahmed, a massive African elephant, whose remains are preserved at the National Museum in Nairobi and in whose name revenge must be sought.         Richard Wiley is a craftsman. His eclectic cast of misfits plays out an engaging story  in a superbly wrought atmosphere of post-    colonial tension and drama.