Great opening paragraph to set the story. Perhaps usage of non-sight description - smell, taste? - might have enhanced, but a minor gripe.
"This would be your stop, yes?" <- this sounds... very modern, as though we're talking about a scheduled public transport service. I'm not sure that's what you were aiming for.
besides -> beside
called plainly <- this is a strange choice of adverb to me.
"voodoo" <- missed chance for some Althanas-ism! In general the cart driver speaks as though she were a modern cabbie rather than a denizen of Althanas, and thus feels out of place.
Good characterisation for Fenn in the next paragraph. That said, a little tell rather than show?
hefty deer hitched to her cart <- nice! Elk or moose might have read better, as deer are not particularly powerfully built animals, but I like that you gave her a beast other than a carthorse or ox!
thanes -> Thaynes, as we're talking about the established pantheon here.
In your exposition paragraph here, and in the description of the haunted house two paragraphs onwards, you make great use of imagery to set the scene. That said you do fall afoul of telling rather than showing, and in the process, again you miss the chance to make more use of Fenn's senses as he first explores the manse. As such it lacks the ominous atmosphere that you otherwise could have crafted - which in itself might be difficult to recover from in a horror-themed tale.
it's -> its! Only use "it's" when you mean "it is"!
Finally a hint of smell. Once again, though, you're telling rather than showing, although I did enjoy how you ended the post!