Introduction

The Imperium of Man is beset on all quarters by enemies bent on its destruction, but the most insidious and dangerous threat is the one you cannot see. It is this thought that spawned the Inquisition. The Inquisition is an organization devoted to rooting out traitors, heretics, mutants and aliens. The Inquisition only goes to battle when there are threats that standard Imperial forces, including the mighty Space Marines, are incapable of facing. These threats are so pernicious that the Inquisition has full command of the might of the Imperium of Man, from the stalwart Space Marines to the ordering of Exterminatus - the orbital destruction of an entire world.

The Ordo Hereticus (Witch Hunters)
Within the Inquisition, there are Orders that specialize in fighting particular foes. The Ordo Hereticus, or Witch Hunters, are devoted to fighting the mutant, rogue psyker, and heretic. Mutation is an affront to the purity of Man that can and does manifest itself at any time. Meanwhile, rogue psykers can twist the natural order and even call forth Daemons from the Warp. Lastly, heresy knows no bounds and thus requires the most vigilance from the Inquisition to uncover and eliminate. In the end, these very forces could shatter the Imperium if left unchecked.

In their never-ending quest to protect the Imperium, the Witch Hunters have access to the most lethal weapons and agents known to Man. They also have a historical tie to the Adepta Sororitas - the Sisters of Battle. As the Chamber Militant of the galaxy-spanning Ecclesiarchy, the Sisters of Battle are fierce warriors that are equals to their brother Space Marines. What the Sisters lack in genetic enhancement they make up for in faith and devotion. No one is more devoted to the cause and cult of the Emperor than they are.

The Ordo Malleus (Gray Knights)
Within the Inquisition, there are Orders that specialize in fighting particular foes. The Ordo Malleus, or Daemonhunters, are devoted to fighting the Chaotic Daemons of the Warp. Daemons and their followers are and always have been the greatest threats to the Imperium. Their influence can snake into any sector, into any individual, no matter how secure or loyal they may seem. If left unchecked, these forces of Chaos could defile Humanity in a matter of years. Of course, this fact is kept from the citizens of the Imperium.

Because of the dire nature of the threat, the Daemonhunters have access to the best troops, weapons, and characters to fight their secret war. A special Chapter of advanced Space Marines, the Grey Knights, stands ready with powerful abilities to assist the Inquisitors. They can also use killers from the Officio Assassinorum and sanctioned psykers from the Scholastia Psykana. No resource is spared when a Daemonhunter goes to fight.

Gray Knight Military Organisation
Unlike almost all other Space Marine Chapters, the Gray Knights of the Inquisition do not follow the tenets of the Codex Astartes in the matter of force organization. Due to the unique manner in which the Gray Knights are recruited and trained, each warrior progresses through a series of preordained ranks and will operate in a particular squad led by an individual of higher rank rather than being assigned to a particular battle company. These squads may be called upon to act independently from the main body of the Gray knight force, and have to operate at full efficiency even when light years away from the rest of their Chapter. As such, the leader of each Gray knight squad is obeyed immediately an without question by those under his command.

When a new recruit has completed the lengthy and grueling introduction into the Gray Knights, he is honoured with a suit of power armor and assigned to a Gray knight squad under the command of a Justicar. At this stage he his permitted to wear his own personal heraldry. If he survives long enough to become a Justicar himself he will lead a quad of Gray Knights in battle, perhaps specializing and joining a Teleport Attack or Purgation Squad. The few who prove themselves truly worthy and and master their psychic talents over centuries of active services will be granted Terminator Honours and take to the field in one of the hallowed Tactical Dreadnought suits of the Gray knights. Those who excel amoughtst even these superhuman individuals are promoted to the rank of Brother-Captain. It is the ultimate goal of the Gray Knight to reach the rank of Grand Mster, but few survive long enough to achieve the complete mastery of their psychic potential necessary to be granted this supreme honour. Those who do so are truly amongst the greatest of the Emperor's servants.