First rate yarn against the most realistic Caribbean background I have found in fiction or travel books. One can see and feel and hear and smell the place, an island placed near Dominica. And the story takes place on the day of the year when carnival prevails, and the tiny handful of whites, dregs of society, British officialdom, planters, rub elbows with the seething native population of blacks, dangerously close to the primitive with too thin a veneer of civilization to hold up against the coming to a head of drama on that day. The problem of mixed bloods is a thread throughout. It is a melodramatic tale, convincingly told -- and a bitter indictment of white rule. Robb White has written two adventure stories for teen age boys, one of which won the Herald-Tribune award last spring. He has a gift for spinning a story -- and he knows his setting.