He was everything she wanted. She was everything he needed to lose. When Elena married Daniel Marsh she believed she had found the one. Successful. Attentive. Warm. The kind of man other women told her she was lucky to have. She stopped feeling lucky approximately eight months ago. Then a Christmas card arrived with one line inside it. Ask him about Caroline. Caroline was Daniel's first wife. She died three years ago. Accidental overdose. Daniel never spoke about her. Elena never pushed. Now she is pushing. And what she finds buried beneath the perfect marriage - in a safe hidden behind a bookcase, in a notebook with the word resolved written beside a dead woman's name, in messages between her husband and someone who calls themselves M - will destroy everything she thought she knew about the man she married. About the woman who came before her. About what is being planned for her right now. Elena is an architect. She builds things that hold. She sees structures that other people miss. She notices when something is not where it should be. And she has just found the blueprint for her own disappearance. The question is not whether Daniel is dangerous. The question is whether Elena can dismantle four years of careful construction before the timeline runs out. A gripping psychological thriller about dangerous marriages, buried secrets and one woman who refuses to become the next name in her husband's notebook. Perfect for fans of Gone Girl, Behind Closed Doors and The Silent Patient. Some husbands are too perfect to trust.