Tales from Potterwatch

by Mythopoeist1

There's an awful lot of stories where Harry Potter ends up traveling to another universe. At some point, you have to ask yourself what would happen if these universe-traveling boys-who-lived decided to work together. This is the answer. I do not own Harry Potter, as I am not British, a woman, or a transphobe.

5. Chapter 5

Foreword:

Infinity is weird- there's different amounts of it, and some values that go even higher. Those are called "transfinite", and they only appear when dealing with ordinal numbers. There's tons of videos that go more in-depth, but I won't get into that.

Multiverse Navigation 101

Good morning recruits, my name is Hazel Potter and I'm in charge of Multiverse Navigation for this particular branch of Potterwatch. In this course you will learn the basics of intentional travel between universes, as well as the differences between ordinary alternate universes and other, stranger worlds. The first thing you need to remember is that the Multiverse is infinite, so once you leave a universe without knowing its coordinates, you can't get back on your own. Since the Multiverse is infinite, so is Potterwatch, meaning that there's an infinite number of Potterwatch branches. You'll need to get the unique ID for this branch branded onto your soul if you ever want to find us again.

I know, it sounds worse than it is. We need to use part of your soul because we're dealing with an infinitely long ID, and those don't really play well with ordinary matter or energy. A soul is the only thing capable of storing transfinite amounts of information – not even an entire universe dedicated to data storage would work. Believe me, we've tried. Fortunately, since the soul is transfinite, the branch ID brand will take up exactly zero percent of it, leaving you with plenty of room for your personality, memories, and soul bonds.

When navigating the Multiverse, you have to remember that not only is there an infinite number of worlds out there, but that each of those worlds splits off into an infinite number of alternates with each event in that world. Picture one of those probability trees they use in Arithmancy, except each node has an infinite number of branches, and the distance between two levels is infinitesimally small. You can see how that would get out of hand rather quickly, so instead of navigating by universe, we pick a root universe and group it and its child universes together. We call this a bundle because it's the equivalent of taking a single node in that infinite decision tree and bundling it together with everything coming off of it. In other words, a reality bundle is a subtree of the multiverse.

Arithmancy can only take you so far, so when we're sending you to a bundle we don't already know about, we use people with strong divination talents to pinpoint the exact location of where you need to be. Some of you will be helping us with that- you don't actually do the travelling most of the time. You just aid in the portal opening ritual, doing what your instincts tell you is right. It's designed to reach inside your soul and read coordinates from there, so everyone else also needs to know how to do it. In case of an emergency, you can use the Potterwatch Id brand as portal coordinates to return here.

Let's stop for a quick lunch break, then we'll cover the basics of opening a portal between universes. No, you can't make any Rick and Morty jokes. I've heard them all and I assure you they aren't as funny after the 80th time.