At the Convent of Sweet Mercy, young girls are raised to be killers. In some few children the old bloods show, gifting rare talents that can be honed to deadly or mystic effect. But even the mistresses of sword and shadow don't truly understand what they have purchased when Nona Grey is brought to their halls. It takes ten years to educate a Red Sister in the ways of blade and fist, but there is much more for Nona to learn than the arts of death. Among her class she finds a new family - and new enemies. Despite the isolation of the convent, Nona's secret and violent past finds her out, drawing with it the tangled politics of a crumbling empire. Beneath a dying sun, Nona Grey must master her inner demons, then loose them on those who stand in her way.