That is ominous- Anders has never been one to hide his emotions well- and with Wardens not faring well? There are many causes but this deep underground only one stands out.

"For how long?" To become a ghoul is-

It is a terrible fate, from what he remembers. Cousland and their merry band wandered into years ago but to think of Nathaniel like that? Not too far of a stretch. It is the fate of every warden.