During Eleanor and Anthony Edevane's 1933 Midsummer Eve party, their daughter, Alice, a budding writer, falls in love for the first time. However, the night is fated to be remembered in tragedy as Alice's infant brother, Theo, is kidnapped from his crib. The Edevane family abandons the country house, never to return. Seventy years later, Detective Constable Sadie Sparrow discovers the overgrown house, and seeks out the now-elderly and famous Alice for answers and the uncovering of old secrets.