Pariah: Ravenor vs Eisenhorn (Warhammer 40,000) by Dan Abnett

Description

Inquisitor Gideon Ravenor returns to action to hunt the most dangerous enemy he has ever encountered, a disgraced inquisitor, driven by obsession to bind daemons to his will and consort with heretics. For Ravenor, this is more than just a manhunt; it is personal. This foe was once his greatest ally and most trusted friend: his old mentor, Gregor Eisenhorn.