Kind of Cruel is the 7th book in the very popular Zailer & Waterhouse series by Sophie Hannah. In this installment we meet Amber Hewerdine who suffers from chronic insomnia, leading her to call a hypnotherapist as a very last resort. Not feeling confident that this will help, she attends her first session feeling skeptical. Coincidentally, she meets Detective Charlotte Zailer who was also waiting to see the counselor for smoking. Her and her husband Simon Waterhouse are the crime solvers of which this series was named. When the hypnosis causes Amber to say the words "kind, cruel, kind of cruel" she has no idea what they mean or where she saw them written, but the next thing she knows, she is picked up by the police for questioning regarding the murder of a local school teacher, Katherine Allen.
The point of view shifts back and forth between Amber, the therapist, and each of the detectives involved with the case, so readers must be paying very close attention. This is not a light read, but it's got psychological insight, a twisted plot and intrigue.