That should have skeleton placeholder mobs, from the looks of it. Maybe it was just unlucky respawns?
could be, it was over a year ago that i successfully did it. The way i remember it is that it only spawns in the place where there is a human rogue/brigand or something in the ruins and spawned either at nightfall or midnight that 1 time. The info i could find on it was a post from 2006
I did attempt to do the quest on the beta server and cleared out about 4 rounds of skeleton spawns waiting for it to spawn in that 1 spot and never saw it either, but it could of been bad luck.