1894, Sir Montague Fowler, warden of St Michael's College, Oxford, dies from apparent natural causes. Before long vicious rumours begin to circulate about the actual cause of his death, and an autopsy reveals that Sir Montague's body was full of the deadly poison mercuric chloride. Detective Antrobus of the Oxford city police is summoned to investigate. Who would benefit most from the warden's death? His three children are all in desperate need of money and each are embroiled in their own scandal: his son John is a secret gambler with enormous debts, daughter Frances has fallen into the clutches of a blackmailer, and son Timothy had stood by and watched his rival in love drown. Antrobus's list of suspects grows as it seems everyone had something to gain from the death. Aided by pioneer physician, Sophia Jex-Blake, the detective sets about unravelling the truth behind this Oxford tragedy.