Death is a frequent visitor to the Royal London Hospital. But this is the first time that a murder has occurred within these walls... Prudence Barrymore, the best nurse at the hospital who saved the wounded during the Crimean War, was strangled. Who needed the death of a sister of mercy? For an answer to this question, member of the board of trustees Callandra Daviet turned to her old friend, former police officer and now private detective William Monk. Miss Latterly, who was also a nurse in the Crimea and knew the deceased well, undertook to help him. Their private investigation identified the circle of people who had motives for the murder. And this made Mrs. Daviet very worried - because the hospital surgeon with whom she had long been in love was among the suspects...