No, my adventure involved falling into the water and being infected with a cold that wouldn't abate.

[Not until much, much later.]

Magic didn't even cure it.

[The undead she had seen were strange but unnerving. Though, it terms of strategy, it seemed unlikely they would remain. Not in a place they already conquered.]

It's possible that once they claimed this place, they wished to conquer others. They likely saw no need to leave anyone to oversee it.