Mysterious murders take place at Nightingale House, an educational institution in the very center of England where sisters of mercy are trained. An elusive criminal brutally deals with girls who are called upon to ease the pain and suffering of others. It seems that he is trying to prove: the best cure for all diseases is death... Adam Dalgliesh will be able to stop the killer only if he manages to penetrate the secret world of the Nightingale House - a world of scandalous passions, sex, violence and... shame.