Beth lives by Camden Lock with her partner Sol and their daughter Fern. Life is peaceful, but Beth is troubled by increasing unease. It could be to do with her mother's disappearance years ago. It could be her sense that Fern is keeping secrets from her. So she goes to therapy. Dr Tamara Bywater is there to help her patients, and soon their sessions become the highlight of Beth's week. But Beth is in over her head before she realises that Tamara might not be all she seems...What if the person you trust the most turns out to be the greatest danger of all?