So I’m playing Single Player (Offline), and I had a Dancer III disappear on me last week. I had two Dancer III’s entertaining my row of 15 or so Fighters, and one day, one of them simply wasn’t there when I started the game.
I checked the Thrall Pot, which indicated that both of the Dancer III’s were still using it, and a couple days later I noticed I could hear “water bubbling” sounds like you hear when swimming/breathing underwater, around the location that the Dancer III disappeared.
So I enabled Admin mode to fly and ghost myself through the ground, and lo-and-behold, there was my Dancer III, about ten meters underneath the ground surface, just floating there in a swimming pose (my base is next to the lake at the top of the northern aqueduct, so she would’ve been below the level of the nearby water).
So I was able to retrieve my Dancer III in my Single Player game, but someone who is playing on official servers would not have that luxury, and the inaccessible thrall(s) will still count towards the thrall limit.
Sorry but I’m not able to reproduce this one; I’ve been playing for months and this is the first (and only) time I’ve seen it happen.