The Shadows

As much as I’d prefer not to, I figure my birthday is fast approaching and I better try to decipher some of this gibberish my father left behind if I’m to have any hope of controlling whatever the hell monster I’m going to turn into.
So here we go, entry numero uno in “Isuel’s Reluctant Studies in Genealogy.”
This old binder of his is full of so much crap, none of it apparently organized, that it almost seems pointless to try and go about my reading in an organized manner. But I guess the point is to always be better than my father, so I’ll give it a shot.
I am going to pick something easy to start though - and since there seems to be an abundance of notes on them, let's start with “the shadows.” I say ‘abundance of notes’ like that’s what matters, but truth be told, I’m a bit curious myself. It’s been ages since I’ve seen the old reynard, but I can’t block out all his muttering about ‘traveling the shadows’ and related tosh.
See, the old man was convinced that there are still paths into Underhill. Don’t get me wrong, I’m sure there were. And probably still are, but there can’t be all that many left. I mean, to hear the talk, there’s barely even any Underhill left. And my dear old dad, hatter that he was, swore up and down that if he could figure out how to ‘travel the shadows’, that’d be a sure fire ticket into Underhill. Crazy old coot.
And what, you may ask, does he even mean by ‘the shadows”? Just as it sounds. Guy wanted to like, turn to shadow or something and then move within the other shadows. Swore up and down that if he could figure it out, he could get to any place in any dimension, easy as you please and faster’n you can blink.
To be clear, he never actually mentioned “turning into shadow,” but I fail to see how else a body could teleport via these mysterious shadow lands. He also mentioned, often, how damn dangerous the whole undertaking was. I didn’t really follow, or even try to follow, but sounded like anyone who wasn’t a proper shadow, uh, denizen, wouldn’t make it in and out of the shadows alive.
I guess I’ll just have to keep trying to parse this crap, see if he found anything else out, or if I can safely declare him a madman and move on with this trash fire of an undertaking.
Won’t lie, I am really curious why all the notes about shadows tend to devolve into ranting about cats.