An ominous butterfly house. A sinister legacy. An untraceable killer. In 1921, Marian Arnold, the heiress to a brewing baron's empire, seeks solace in the glass butterfly house on her family's Wisconsin estate as Prohibition and the deaths of her parents cast a long shadow over her shrinking world. When Marian's sanctuary is invaded by nightmarish visions, she grapples with the line between hallucinations of things to come and malevolent forces at play in the present. With dead butterflies as the killer's ominous signature, murders unfold at a steady pace. Marian, fearful she might be next, enlists the help of her childhood friend Felix, a war veteran with his own haunted past. In the present day, researcher Remy Shaw becomes entangled in an elderly biographer's quest to uncover the truth behind Marian Arnold's mysterious life and the unsolved murders linked to an infamous serial killer. Joined by Marian's great-great-grandson, can Remy expose the evil that lurks beneath broken wings?