Ruth, a loving and beloved mother in an ideal family with three children, is found dead in a pool of blood. But who would want to murder an ordinary housewife, and for what reason?
Lately, psychotherapist Frida Klein has been trying to recover physically and psychologically from an attack that nearly cost her life. Unexpectedly, she finds herself personally connected to the murder case, and when the evidence shows that Ruth maintained a second, hidden life, her family members close ranks in an impenetrable defensive silence. It is time for Inspector Carlson to seek Frida's help in order to uncover the truth.
The chance observation of a patient sets off alarm bells in Frida's mind and she finds herself, without fully realizing it, on the path that leads to a serial killer. Or perhaps all of this is just a symptom of the increasing turmoil in her own mind.
Frida knows all too well that every step towards the killer is a step deeper into darkness, from which there may be no return...