With a dark and sometimes unnerving mixture of elements from “Strangers on a Train” and “Throw Mama from the Train,” this made-for-Showtime movie is occasionally satisfying. I said, occasionally. Unfortunately, most of the comic moments center around sexuality. And the premise of someone destroying another person’s life is a bit unsettling in a world where such deeds are committed more and more often. At one point the female lead drives a wedge between a man and his wife, leading her to divorce him; then she causes havoc at his work, and finally she prevents him from reaching his ventilator before his asthma attack can finish him off. I found little humor in her evil and unpunished crimes, which brought harm to innocent people. “Edgy” is the key word to this script, rather than suspenseful or humorous. Although the leads give fine performances, the adulterous affairs, the kinky sexual situations, the sexual innuendo, the course language and the overall negative feel of the production left me dispirited and anxious to view something a little more uplifting.