Marple is asked by her lawyer, Christian Gilbranson, to visit his step-mother, Carrie Louise Serrocold, an old friend of Miss Marple's, at her country estate. Carrie's husband, Lewis, confides to Miss Marple that he suspects someone is slowly poisoning his wife, and when Gilbranson visits the mansion, he is mysteriously murdered.。Based on the true story of teenagers who deliberately inject themselves with HIV to escape the oppression of "Special Period" Cuba.。