My GM is very lazy and he never provides our Deathwatch team with sufficient intelligence to reach it's goals. Instead he uses unbelievable coincidences to repair the sessions he broke.
For example once we were supposed to go into hive city to find hidden xeno lab and kidnap ethereal kept there. We weren't given information where it's located or even how it looks like. After hours of pointless wandering we stumbled upon tau pathfinder team that actually blackmailed our characters: they demanded oath from the marines made in the name of the Emperor and Chapter that they wouldn't hurt any of them or the ethereal in exchange for location of the xeno lab and joint destruction of it.
Well, we killed them right away in, like, one turn. Xeno forcing a marine to promise in the name of the Emperor and his Chapter? No brainer: kill'em all.
Then we ran into a "random guy" walking down the corridor. I guessed that he was supposed to give us location of the lab, but my friend's character didn't - he shot the poor NPC into shreds with Astartes Rocket Launcher out of boredom. For a second we felt all alive.
Finally we found the lab and the mission started (4 hours after the start of the session), by PURE ACCIDENT in 6 BILLION PEOPLE HIVE CITY.
And that's just one of his missions. Here's the thing: I'd like my character to respond to such laziness of Inquisition (not providing vital intelligence, forcing elite strike force to do "ground work" instead of assigning it to the acolytes, relying on a pure accident in billion Throne Gelt missions) with resistance. I'd like him to slowly question the power of Inquisition and the Imperium and finally, after many internal changes, lean totally towards chaos. How would you do it, so that it would look good and credible? My character is an Ultramarine Tactical, veteran of the tyrannic wars, full of faith in the Imperium. How can he interprete incompetence of his superiors to ultimately question the whole of Imperium?