John Preston brings it back to the basics: a hand on a neck, a boot that needs a spit shine, a trick who leaves with bruises and sweet memories. In books such as the S/M classic Mr. Benson, Preston explored power exchange in all its battered beauty. The sex stories in I Once Had a Master combine a hard-core sensibility with rare psychological insight.In "Authenticity," a top turns down two fawning bottoms in full leather regalia in favor of the sweet-faced novice who offers genuine surrender. In "Pedro," a college boy has a summer affair with a truck driver and finds himself flirting with other men just to provoke his lover’s rage. The lonely bottom in "Interludes" develops his body to perfection, then seeks out the Daddy who will cherish this gift.