WITH AN INTRODUCTION BY PAUL THEROUXThree men meet on a ship bound for Haiti, a world in the grip of the corrupt ''Papa Doc'' and the Tontons Macoute, his sinister secret police. Brown the hotelier, Smith the innocent American and Jones the confidence man - these are the ''comedians'' of Graham Greene''s title. Hiding behind their actors'' masks, they hesitate on the edge of life. And, to begin with, they are men afraid of love, afraid of pain, afraid of fear itself...