In Vienna, a city of artistic and scientific revolution, thousands of women are still dying in childbirth each and every year. Only Dr Semmelweis can see the invisible killer at work, but to stop it, he must convince his colleagues to admit culpability and approve change.

Damned by an establishment that questions his methods, his motives and even his sanity, Semmelweis is haunted by the women he has failed to save. Can he finally convince the greatest doctors of 19th Century Europe to accept his argument – and what will it cost him to make an almost impossible case?