The Last Promise — Douglas Browning

Walter Waner, former university professor and present novelist, is lured by petite but captivating Promise Moss into investigating threats to her and her coterie of sexual companions. Barely having begun, he is confronted with the murder of one of her companions. Untrained in detection, he finds himself groping and stumbling in his effort to find answers. Promise and two of her close friends, gloriously attractive women, draw Walter into byways of temptation and frustration He bumbles on as his very life becomes entangled and transformed.