From the dark streets of Victorian England's North, one woman's scandal threatens an ancient sisterhood of mercy.

Caroline Summers helps people to die. She is a Blackshroud — a member of the select society of women who have dispensed the fatal draught since time immemorial. But in Victorian England, times are changing fast. Caroline finds herself at the centre of a scandal that threatens to bring down not just herself but her whole profession alongside her. Can she find a way to survive? And can she do so without sacrificing everything she stands for?