Inquisitor Bronislaw Czevak is a hunted man. Escaping from the Black Library of the eldar, Czevak steals the Atlas Infernal - a living map of the Webway. With this fabled artefact and his supreme intellect, Czevak foils the predations of the Harlequins sent to apprehend him and thwarts his enemies within the Inquisition who want to kill him. Czevak's deadliest foe, however, is Ahriman - arch-sorcerer of the Thousand Sons. He desires the knowledge within the Black Library, knowledge that can exalt him to godhood, and is willing to destroy the inquisitor to obtain it. A desperate chase that will bend the fabric of reality ensues, where Czevak's only hope of survival is to outwit the chosen of Tzeentch, Lord of Chaos and Architect of Fate. Failure is unconscionable, the very cost to the Imperium unimaginable.