This is that drinking challenge quest, i'll try not to spoil.
During the last leg of this quest you get teleported to a place called Misty Grove and the Man you speak with there teleports you out. All good there. Quest finished normally.
Well, I went back to Morvunskar to nab a chest I saw right underneath the err "Mystical Gate Thingy" and got teleported again to Misty Grove. Note: the chest is directly underneath where the gate is (through the stone floor in a small alcove), so when attempting to get the chest, if you get too close you get auto-teleported.
And now I'm stuck. There is no way out. No fast travel allowed. The Man who teleports you out initially is gone and all that's there are those commoners drinking. :(
I've got a save relatively close to where I was, so not too big a deal to reload, but just wondering if there is actually a way out of there.