When Amber Hewerdine consults a hypnotherapist as a last resort, she doesn’t expect that anything much will change. She doesn’t expect it to help with her chronic insomnia … or to hear herself, under hypnosis, saying words that mean nothing to her: “Kind, cruel, kind of cruel”. Words she has seen somewhere before, if only she could remember where …

She also doesn’t expect to be arrested two hours later in connection with the brutal murder of Katharine Allen, a woman she’s never heard of …