Inquisition - The Inquisition and the Adeptus Astartes: There is also one area of an Inquisitor's remit that is fraught with peril, but is fundamental to their successful operation -- their relationship with the Space Marine Chapters of the Adeptus Astartes. Like the Inquisition itself, the Adeptus Astartes operate alongside the Imperium rather than as part of it.The Inquisition's power extends over the Space Marines, but the Chapters themselves are fiercely independent and not welcoming of outside investigators. An Inquisitor that suspects a Chapter of deviant behaviour must tread carefully.Space Marines have been, historically, extended a lot more latitude than other Imperial forces concerning their organisation and activities. However, the threat posed by a Renegade Chapter is such that they must be constantly monitored. The purity of their gene-seed and the motives of their actions are regularly scrutinised for irregularities.The most traditional, hardline Inquisitors have immense problems dealing with the Adpetus Astartes, simply because they also operate outside the dogma and bureaucracy of the Imperium. What may seem heretical and self-serving on one level can also be viewed as essential to the Space Marines' power. The ability to act on their own, to fight where necessary and to take whatever action they deem fit is intrinsic to the Space Marines' capability to respond quickly and efficiently to emerging threats or to proactively protect Mankind.Unorthodoxy is easily confused with disloyalty, and there have been a few occasions when an over-zealous Inquisitor has instigated a problem where none existed. The Space Marines are rightly justified and proud of their loyalty to the Emperor, but endeavour to remain aloof from the infighting and politics that plague the Imperium.They answer to none but their Chapter Masters and the Emperor Himself, and to have their loyalty brought into question is a great offence. To have forces of the Imperium brought against them is, to the Space Marines, a betrayal of the bonds that exist between a Chapter and the Imperium.It is therefore a prudent Inquisitor that does not rush in. In circumstances where a Chapter is proven to be a threat, it is the most preferable course of action that other Adeptus Astartes are used to combat the threat. Not only is a Space Marine Chapter a formidable fighting force that conventional troops may not be able to confront, but also allowing the Space Marines to deal with each other is invaluable.Space Marines all share a common bond with each other, and a Chapter Master will respond to information that threatens the honour of the Adeptus Astartes as a whole -- for one Chapter to turn Renegade is a smear on the reputation and honour of all Space Marines. It is sometimes enough to be confronted by fellow Space Marines rather than an agent of the Imperium to make a Chapter see the dangerous path it has begun to tread and to change its behaviour.If such criticism were to come from another source, it is likely to prompt a harsh reaction, possibly even compounding the threat. On the other hand, if a situation has reached such a level as to become a genuine menace, the destruction of the Chapter is sometimes the only course left open (such as the Soul Drinkers Chapter).This is no small undertaking, and several other Space Marine Chapters may become involved, either of their own volition or by request, as happened in the Fourth Quadrant Rebellion that led to the Badab War.It is clear then that wherever possible it is best if the Inquisition can deal with a threat using its own resources, avoiding the dangerous entanglements that may result from involving other agencies and military forces.It is for this reason that the Inquisition maintains its own fighting formations, foremost amongst them being the Kill-teams of the Deathwatch Space Marines and the Daemon-hunting Grey Knights Space Marines.