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.