The dual story of Blue Camell rounds the circle again in another dual romance, -- primarily that of Prosper Villa and his lovely Victorine, secondarily -- and not very convincingly- that of his young sister, Anne Maria, and Dale Fontenot. Prosper's grandfather was the agronomist, Brent Winslow, of the earlier book- who perfected the long grain rice which rescued the Louisiana economy, and there are flashbacks to Prosper's mother's sad love story. But Mrs. Keyes has plenty of ingredients here for a full fledged modern tale- set in Louisiana of the '20's, a tale blending the ingredients of romance with the somewhat shabby mystery of the death in the rice bins of a cheap, ambitious little tramp of the bayous. She manages to unravel the mystery just in time to save her hero for a happy marriage, and to jolt young Anne Marie into finally growing up. Not Mrs. Keyes at her best, either as spinner of yarns or (where she seems usually to excel) in creating a warm and living background. But the story moves -- and her faithful following will once again make it a best seller.