The Ordo Malleus is the branch of the Inquisition devoted to the deadliest enemy of all: the daemon. Where other agents of the Imperium may go their entire careers without facing a creature of the Warp, the Inquisitors of this Ordo hunt them deliberately, studying the daemonic so that they may better destroy it.
Formed in the aftermath of the great betrayal that revealed the full horror of Chaos, the Ordo Malleus guards knowledge so dangerous that merely possessing it would condemn an ordinary citizen to death. Its members arm themselves with sacred weapons forged to banish the Neverborn and cloak their operations in absolute secrecy, for panic and heresy spread wherever the truth of daemons becomes known.
When a threat proves too great for a single Inquisitor, the Ordo Malleus can call upon the Grey Knights, the secret brotherhood of daemon-hunting Space Marines who serve as its personal army. Together they stand as the Imperium's last line of defence against incursions from the Warp, waging a hidden war whose victories are never celebrated and whose defeats can doom entire worlds. To be of the Ordo Malleus is to stare into the abyss as a matter of duty.