In the autumn of 1929, a small child was kidnapped from a Lincolnshire beach. Five agonising days went by before she was found in a nearby village. The child remembered nothing of these events and nobody ever spoke of them at home. It was another fifty years before she even learned of the kidnap. The girl became an artist and had a daughter, art writer Laura Cumming. Cumming grew up enthralled by her mother's strange tales of life in a seaside hamlet of the 1930s, and of the secrets and lies per