Attacked by troll brute from far away
I was on lvl. 2 of a dungeon, filled with ogres and troll brutes. A troll brute began to attack me with a great club, so I retreated to inside the dungeon walls (had the earth shard). I retreated to places where it was impossible that he got me (inside walls, far away from the place where I found him, and no enemies in sight) but I kept getting messages of being attacked with a great club and losing HP. I eventually died, reportedly killed by a troll brute.
I suppose that there are no invisible troll brutes that pass walls so I'm guessing a bug...