I Am Slaughter is the first volume in The Beast Arises series of novels.
It is the 32nd Millennium and the Imperium of Man is at peace. The Traitor Legions of Chaos are but a distant memory and the many xenos races that have long plagued Mankind are held in check by the Space Marines. When a mission to exterminate one such xenos breed on the world of Ardamantua draws in more of their forces, the Imperial Fists abandon the walls of Terra for the first time in more than a thousand standard years. And when another, greater, foe strikes, even the heroic sons of Rogal Dorn may be powerless against it. The Beast Arises...and it is mighty.
- I Am Slaughter (Novel) by Dan Abnett