Death might be commonplace in 1857 in the Royal Free Hospital in London's Gray's Inn Road, but murder certainly isn't. When the body of Prudence Barrymore, a gently bred, dedicated and passionate nurse, is discovered stuffed into a laundry chute no one - high born or low - can be beyond suspicion. But the police seem determined to concentrate their efforts on proving Dr Kristian Beck the culprit - because he is foreign. Concerned and unhappy with this state of affairs, Lady Callandra Daviot of the Board of Governers asks Investigator William Monk to pursue the case.
Monk, frustrated by the lingering traces of amnesia caused by an accident, agrees, and calls upon his old colleagues to aid him. Hester Latterly, an independent young woman who served with Florence Nightingale in the Crimean War, knew the dead woman there; Hester's profession provides the perfect cover for her to obtain work at the Royal Free. And Oliver Rathbone, a brilliant barrister, who is brought in as counsel for the defence. But under the ever-present shadow of the gallows, and inching towards the appalling solution, the three begin to despair of justice ever prevailing.