So I had an idea for a campaign that I like, but am unsure if it's fair to the players or not. Submitted for opinions/suggestions:
The acolytes are recruited and progress normally until some particular mission where they somehow meet another Inquisitor or cell of more advanced acolytes. They work together out of necessity or whatever comes convenient to me as GM at the time. After such time, before splitting ways, the other acolytes/ Inquisitor offers them a favor or service or something to make another contact. Encourage said contact through typical devious GM ways. After second contact, have acolyes or Inquisitor offer to induct PC cell into their sub Ordo (or whatever name I come up with for it). Having advanced they now have leave from their normal chain of command to pursue their own leads, and get some good leads on chaos cults from the other group, who seems to be too busy to follow up on all of them. These leads bring in big chatches and bring down major plots, and the relationship goes well for PC cell. Then, after awhile, PC cell gets info on cult that starts to bring them back around to the Inquisiton, eventually into direct conflict with their erstwhile benefactors when at the climax it is revealed the Inquisitor was really a cult leader infiltrating the Inqisition, and the acolytes were his main cult members. All are legitimate Inquisitorial agents in good standing, but are also double agents. Many of the cults the PC's eliminated were rivals to this group and with the PC's help, they have managed to imbezzle tons of money and material to fight against the Imperium.
Is it fair to the players to have them help out chaos cultists that they think are good acolytes that maybe they look up to before because they have a good reputation and are well liked. before their treachery is revealed, and even after many other would not believe the PC cell?