"Birthday Present" by Arnold Marmor is a crime fiction story written during the early 1950s. The narrative centers around a tense and morally ambiguous situation involving an illicit love affair that culminates in a shocking act of violence. The book deals with themes of love, betrayal, and the lengths one might go to for another person, set against a backdrop that combines elements of science fiction with a noir atmosphere. The story unfolds primarily through the perspective of the unnamed protagonist who is infatuated with Diane, a woman married to a man frequently away on Mars. As Diane's birthday approaches, she devises a sinister plan that involves her lover killing her husband, presenting a thrilling blend of romance and crime. The protagonist finds himself torn between his love for Diane and the moral implications of committing murder. The tension escalates when the plan is set in motion, leading to a climactic moment filled with unexpected twists, culminating in a shocking revelation that turns a birthday celebration into a chilling and unforgettable scene. (This is an automatically generated summary.)