The guard at the main gate in the Courtyard won't let me through even after I've found the corpse of the Jailer at the bottom of the well and reported back to the Commander. He keeps saying that until the Jailer is found no one goes through.
What else am I supposed to do?

I'm not certain, since I too could never get through that gate, but I suspect that it isn't an actual location. Might want to check with the developers or the beta testers, but it seems to be more of a flavor piece.

Yeah now that I'm more ahead in the story I think so too (maybe a future location?). Thanks for the reply!