[1.0.5] Assasin Lord disappeared. Completely.

[belmarduk]

I have no idea what caused this bug. I was playing a Dwarf Berserker, I was level 9 when I entered his floor. There was a gold chest a few tiles away from the entry that I opened and had no enemies inside. I initiated the fight by attacking the leftmost lackey (I can't remember what monster type this is), the one closest to the entry tile. As usual, the room became aggressive, and the assassin lord entered stealth. The problem is, he never exited stealth. I checked every tile of the map, I tried talking to the merchant, nothing. He was just gone. I had to recall out of the room because there was no way to escape the boss just disappeared with the exit tile.