August 1939. Thirty-year-old Hetty Cartwright is tasked with the evacuation and safekeeping of the natural history museum's collection of mammals. Once she and her exhibits arrive at Lockwood Manor, however, where they are to stay for the duration of the war, Hetty soon realizes that she's taken on more than she'd bargained for. A gripping and atmospheric tale of family madness, long-buried secrets and hidden desires.