'KOKO ' Only four men knew what it meant. Vietnam vets. One was a doctor. One was a lawyer. One was a working stiff. One was a writer. All were as different as men could be - yet all were bound eternally together by a single shattering secret. And now they are joined together again on a quest that could take them from the graveyards and fleshpots of the Far East to the human jungle of New York, hunting an inhuman ghost of the past risen from nightmare darkness to kill and kill