Something happened on Madeline’s 14th birthday, something so traumatic that it triggered her mental breakdown. Many years later, she still can’t – or perhaps won’t – recall the events of that night. A charismatic new psychiatrist, Dr Lucas, believes he can unlock her memory by taking her step by step through the preceding year, when her father moved the family to an island he was certain God had guided them to. Money was short, her mother often unwell and her father a volatile presence. Yet Madeline loved their rural idyll, sensing God in every blade of grass; and when things started to go wrong, she thought she knew how to put them right. But as Dr Lucas unearths the past, it becomes apparent that she was seriously misguided – and that he is treading on very dangerous ground.