"Well, the ones we've actually visited have generally been realities where events in the past have gone just slightly differently but the device we used to travel that way did show us some places that differed by considerably more than you might expect for that before it was destroyed."

"Well, that's not something I'd ever considered was possible."

"Our people have found a lot of strange things since we reopened the Stargate on our world. That mirror has to be one of the weirdest though. It probably saved our world too. A member of our of our teams accidentally went through the mirror and got information from another reality about an attack that was apparently about to happen in our reality too. That information allowed them to launch an unapproved mission to investigate and ultimately thwarted that attack. I don't think we'd be here if they hadn't."

"Gods preserve us. I suppose that's not actually much different from prophecy, in effect, but my skin crawls thinking about what it would take to do it, and Who could be responsible."

"According to some theories that's just how things are, everything that can happen does happen just not exactly here. Those theories aren't supposed to be compatible with things like the mirror existing but the Stargates and some of the metals we've found shouldn't be possible by our old understanding of the world either."

"Everything that can happen, does? I'm not sure I like the implications of that, either. Wouldn't that mean our decisions don't matter?"

"I think it's a matter of perspective. The theory is based heavily in the notion of probability so there are many more worlds where a piece of fruit doesn't appear in midair above the table during our conversations than ones where one does. And similarly, the sort of person you are and the decisions you're likely to make influence what sorts of worlds are more likely and therefore happen more often."

"...I'm going to think that over some other time."

"Probably a good choice. I try not to think about the implications much, whatever the truth is the world in front of me is still real and my choices in this world matter to this world."

"The Ice Court and Verenans - and Wizards, especially Wizards - like to argue about what 'real' means. The most reassuring answer is 'the thing that magic and Chaos aren't, that reasserts itself when spells pass'. But the land is the land and the world is the world, whatever word we use for it."

"Yes, there's a similar phrase among the scholars on my world who study such theories, it all has to add up to normality. That after all the complexities are accounted for everything will eventually look more or less like everyday people expect it to look."

"A simpler proposition there, if I understand right, where Engineer's rules can be relied on all the time. But yes, whatever we see will continue to affect our futures in much the way it always has. ...That may even be true in the Realm of Chaos, though certainly none of us could easily comprehend what passes for 'normality' there."

"Yes, I suppose it would be harder with magic involved."

"It's worse than that. The progression of cause to effect is extremely unreliable if you pass the Chaos Wastes and approach the true Za. It's said - and said often, by many, but they're all mad by the time they write anything down - that what happens in the realm of Khorne, for instance, is first and foremost what Khorne wants and only secondarily follows any other rules."

"Teodor said it was unwise to say certain names but is that one of the Gods of the Za?"

"Teo, really? I suppose it's better than making them too incautious. But yes, he is one of the Four Powers of Chaos, whose collective Realm of Chaos is Za. The Violent, the Bloody, the one whose cultists you met briefly on your arrival. The only prayer he likes is 'Blood for the Blood God. Skulls for the Skull Throne.' and that tells you everything you really need to know about him outside a tactical assessment of his servants. The one we think might have been involved I named a minute ago - the Architect of Fate, the Changer of Ways, the Plotter and the Schemer, hider of secret knowledge and patron of all the most dangerous sorcerers."

"Well, I can understand how that might lead to a degree of paranoia. You said there were four though."

"Yes, I was just taking a moment to consider whether I should. It's true that saying their names can draw their attention, and usually only when something else nearby already has it - absolutely be entirely superstitious about it if you find yourself in Praag - but not always. But it's worth it."

"'Grandfather' Nurgle is the Plaguelord, Fly Lord, Ur-Father, the Diseased, source of pestilence, rot, decay, and slow death of all other kinds. His servants are perpetually diseased and feel all the pain but stay unhampered by it. Slaanesh, Prince of Pleasure and Lord of Excess, the Tempter and the Obsessed -  or Obsessive. Most of his-her-their followers start out as bored hedonists in the south, and there's little about what makes life enjoyable that can't be perverted to his-her-their worship if you indulge too much in it. Physical pleasures, obviously, but also performance, even fine craftsmanship."

Oh great another anti-sex religion. Well maybe. "That last sounds hard to work around. Are there guidelines for what too much is or how something is more likely to draw their attention?"

"Nothing truly reliable. But the Tempter is the least common problem among military men, and relatedly among Kislevites. Most accounts of corruption by the Obsessive indicate a progression of escalating desires, like a drug addict who requires larger amounts over time, and others catching you early would likely be protective. Generally if you're staying within your society's normal bounds it's unlikely to be a risk; I think that's still true for those from societies where the magic is thinner and Chaos influence weaker, which would indicate it being true for you as well."

John just nods at that.

"Oh, I mentioned places to be more superstitious - there are also times. Mostly on nights, when Tenevluna* is shining. Teodor, have you explained Tenevluna?"

*Shadow-Moon, Morrslieb the Chaos Moon

"No, hasn't come up yet since the days are long."

"Right. Staryaluna* is a nice predictable moon that has a sensible cycle like the seasons, twenty-five days from full to full and smooth transitions to dark and back in between. Tenevluna... isn't. There are only two times a year where it can be predicted, just about six months apart, and it's never truly full any other night but it might be dark tonight and half-full the night after and then dark again the night after that. And when the winds of magic blow strong, it might be dark here and near-full five miles east. It's green and uncanny and the dwarfs suspect it's made of the congealed stuff of Chaos. If it's anywhere close to full, that's as bad as Praag and Za is close. When it's full, it's only a few inches away in an unreal direction, and can be punctured through if the wrong thing happens."

*Old-Moon, Mannslieb

"That almost sounds like higher dimensional geometry except it sound far too consistent and uniform for most hyper-objects."