This is material from the archives of Gregor Eisenhorn, an epoch-making work that includes all of Dan Abnett's stories about the famous inquisitor. These stories, many of which have never before been published in print, have been assembled by the author to both complement the popular Eisenhorn trilogy and act as a monumental prologue to Magos, an all-new full-length novel about the Inquisitor. Inquisitor Gregor Eisenhorn spent his entire life in the dark and dangerous corners of the Imperium in pursuit of heretics and chaos-worshippers. But can a person follow this path without succumbing to the temptations of the warp? Is Gregor Eisenhorn still loyal to the Throne, or has he fallen victim to the temptations he hunted for? The most famous anti-hero of the Warhammer 40,000 universe finally returns in a new novel, where he will not only battle an old and implacable enemy, but also face the darkness that lies within his own soul.