1940. At Yew Tree House, recently widowed Adelaide Stride is raising her two daughters alone – but it’s not just the threat of German invasion that keeps her up at night. She’s surrounded by enemies posing as allies and, while war rages, she grows sure that something terrible is about to happen. 2023. Soon after Stella Darnell begins her holiday at Yew Tree House, a skeleton is found in a pillbox at the bottom of the garden. The bullet hole in the skull tells her that the person was murdered. This triggers the unravelling of a mystery 80 years in the making. Soon, Stella will learn that Adelaide was right to worry – the fighting might have been happening abroad, but the true enemy was always much closer to home.