The Imperium of Man has stood inviolate for 10,000 years. Its uncountable worlds are home to a vast array of servants who stand as the only bulwark against the encroaching darkness. From each of them it demands a high price: total servitude to the God-Emperor. Their hands forced by the opening of the Great Rift, these servants move to intercept the enemy and prevent loyal worlds falling. Shield Captain Cartovandis of the Adeptus Custodes must travel across the galaxy to uncover the truth behind a mysterious distress call from the world of Vorganthian. The righteous warriors of Sister Superior Augusta wield their holy wrath as a sword, cleaving the stain of the heretic and the mutant from the planet Lautis. Meanwhile, the dogged soldiers of the Astra Militarum must face creatures of nightmare made real with little but their inner mettle to protect them on the world of Regallus. If any of these worlds should fall, the harrowing consequences will echo across the Imperium.