The Adepta Sororitas of the Sisterhood of the Last Candle have for centuries vigilantly guarded their sanctuary planet, while striving to decipher the visions that appeared to their founder in agony. Outsiders are not welcome here, and yet they arrive. The survivors of a selected company of the Astra Militarum, which suffered heavy losses in a collision with a deadly xenos entity, fly to the Candle World, harboring hopes of healing. Accompanying them is a woman no stranger to the Last Candle—Sister Hospitaler Asenath Hyades, who turned her back on her former order decades ago. As the seekers approach the sect's stronghold, malign forces awaken among the planet's storm-wracked spiers, but the most insidious shadows lurk within souls of pilgrims.