Seventy-four-year-old widow Mrs. Moffat lives in a quiet and idyllic California town, accustomed to routine and solitude in her country home. But everything changes when she runs into a charismatic young transient in church one Sunday morning. He claims to be Simon Warren, the son of a former neighbor and the best friend of Mrs. Moffat's own grandson, who mysteriously vanished years ago. Longing to repair the emotional wounds of the past, the enchanted Mrs. Moffat welcomes Simon into her home. But he's not received nearly as well by her friends or her granddaughter, Zen, whose suspicions about Simon, and the potential threat he poses, are willfully ignored by her grandmother. Now, as the young man calmly insinuates himself into a comfortable new life, a test of wills between the stubborn old woman and her increasingly apprehensive granddaughter begins. What no one understands is that Mrs. Moffat isn't a silly woman: She knows precisely what she wants from her unlikely "friendship" with the untrustworthy Simon. But as a dawning fear arises, Mrs. Moffat, Zen, and perhaps even Simon will find themselves in an inescapable trap of their own making.
Edgar Award–winning Charlotte Armstrong (1905–1969) was one of the finest American authors of classic mystery and suspense. The daughter of an inventor, Armstrong was born in Vulcan, Michigan, and attended Barnard College, in New York City. After college she worked at the New York Times and the magazine Breath of the Avenue, before marrying and turning to literature in 1928. For a decade she wrote plays and poetry, with work produced on Broadway and published in the New Yorker. In the early 1940s, she began writing suspense. Success came quickly. Her first novel, Lay On, MacDuff! (1942) was well received, spawning a three-book series. Over the next two decades, she wrote more than two dozen novels, winning critical acclaim and a dedicated fan base. The Unsuspected (1945) and Mischief (1950) were both made into films, and A Dram of Poison (1956) won the Edgar Award for best novel. She died in California in 1969.