Verity and Meredith live with their fragile artist mother, Allegra, in an ancient house on the West Wales coast. The house creaks and groans with the weight of its history, but the girls love it and never want to leave. Meredith discovers a sewing box. Once open the box releases the ghost of Angharad, a Victorian girl-child with a horrific secret. Forced to abandon Gull House for London Meredith struggles to settle, still haunted by Angharad. The girls grow apart, losing their closeness along with the shared history of Gull House.