In mid-19th century London, a young nurse is found brutally strangled at the Royal Free Hospital. One of the hospital's Board of Governors, Lady Callandra Daviot, engages her friend former Inspector William Monk to investigate the killing. The victim was not an ordinary Victorian nurse, most of whom were poorly educated, morally suspect, and distinctly lower class. Rather, the dead woman came from a middle class family and was an outspoken professional who had worked side-by-side with Florence Nightingale in the Crimea.

In fact, Nurse Prudence Barrymore had had pretensions of studying to become a doctor--an unthinkable goal for a Victorian woman! As Monk and his colleague, Hester Latterly--another Crimean nurse--investigate the inner workings of the Royal Free Hospital, they soon discover a quagmire of secret passions and deceit.

Monk gains access to letters from Nurse Barrymore to her married sister that appear to incriminate Sir Herbert Stanhope, the hospital's leading surgeon and a paragon of propriety. Was Sir Herbert Nurse Barrymore's secret lover? As Sir Herbert's trial progresses, it appears that he was, but then events suddenly take an unexpected turn.