After a thousand years, violent warp storms have receded from the Calaphrax Cluster, and an ancient battlefront in the war against Chaos has again been opened to the universe. Now, multiple forces risk complete immolation to attack the sector - drawn by the lure of ancient relics, lost knowledge, and powerful megaweapons, buried for aeons. Chief among those forces, the fearsome Dark Angels, emerald-armored Space Marines, shock-troopers of the Emperor's Imperium and indomitable defenders of humanity. But Chaos stirs in the warp, and the Dark Angels will not be alone for long! Into this grim warzone, we follow Balthus, a Dark Angel initiate, newly-elevated to the rank of Marine, as he is baptized on the bloody battlefield - and as he uncovers the price his Chapter has paid for victory in the distant past. Alongside him fights Interrogator-Chaplain Altheous, a sombre and dedicated warrior, burdened by knowledge and the truth of his chapter, whose beliefs are tested on Calaphrax as never before. And, navigating a maze of shifting loyalties and suspicions: Inquisitor Astor Sabbathien, convinced that Balthus and all Dark Angels teeter on the brink of heresy. Determined to expose them and root out the taint of Chaos, she and her Acolytes have followed the Marines to Calaphrax - and into the jaws of the warp! Based in the universe of the ever-popular miniatures game, novels, and videogames, this new ongoing series is perfect for both the hardcore Warhammer 40,000 fan and the complete newcomer! Armor up, offer up a prayer to the Emperor, and deploy your drop pod into the very heart of the enemy! Collects Warhammer 40,000: Will of Iron #1-4.