Kerstin Krist arrives at the vine-covered Lydstep Old Hall in rural Essex to care for John Cosway, a former mathematical genius, who has been diagnosed with schizophrenia and kept under heavy sedation. John is the sole heir of the immense Cosway estate. As he takes his daily walks or sits quivering in a labyrinthine library, the rest of the family plots their own ways of coming into the fortune. It is classic Barbara Vine – an absolutely enthralling tale that keeps turning and twisting until the very last page.