When a brutal dance marathon in the suburbs of Boston in 1932 turns deadly, Dr. Haley Higgins is surprised to discover the deceased is the widow of a man whose body still lies in the cold cabinets of her morgue. She has reasons to believe the man's death wasn't natural, and now, with his wife having succumbed to the same symptoms, her convictions of foul play are stronger than ever. With the help of investigative reporter Samantha Hawke, Haley works to determine which contestants in the dancing contest had means, motive, and opportunity—and, most of all, how to keep the killer from striking again.