Half of this Orostachys is gone now. The leaves are very tiny, a slug could polish one or more off very quickly. So far whatever is doing it has not touched the offsets all round the main rosette. I sure hope it can make it through the winter with just half the plant intact. I'm putting slug bait out hoping that is what the problem is.
I had terrible dreams last night. I went out and the beds were covered in huge, fat slugs. I had this little strip of copper sheeting and was going around slicing the slugs in half with the copper. When I woke up there still was a kazillion more slugs out there. Now I'm afraid to go look at the beds this morning.