Okay so the Mystery is what controls all ski lodges. It picks who the murderer is, it controls the murderer's impluse to, well, murder. It also controls the fact that the CBer's can't figure out who the murderer is until the very end.  The CBer's can't remember that they are in a ski lodge, and that it isn't real and their friends aren't actually dead. Controlled once again by the Mystery

As you read when the CBer's talked about the Mystery that it affected The Ski lodge hosts.  This is partly because the hosts, in a sense, aren't real.  They are... to put it simply, Kids of the Mystery. Therefore because Lily and Cassy were related to the Mystery it affected them when it was breaking.

As for how it functions, It would seem that the Mystery is an invsible force that is in all Ski lodges.  Working to make sure that the idenity of the murderer remains secret and that it isn't found out until two people are left.

I hope this covers your questions?

For a semi unrelated note, Lake Lelillo is really good! Have you read Micearenice's first book, The Farm Story?

*jumps in dramatically*

HELLO! 

The Mystery is, to put it simply, the reason ski lodges exist. Mice invented this. 

From moondemon's ski lodge, it was described as a shadowy person with glowing eyes. In Peculium's, it was a man, who seemed not to speak. In mine, it was described as a whirling tornado. So, I conclude that it shapeshifts- just keeps the 'dark and evil' theme. 

The Mystery is what chooses the murderer. It's like a telepathical link, where the Mystery is controlling the Murderer to make it do bad things. 

It's also the weak point of a ski lodge. It makes ski lodges break and become more weak- I suppose that this can be played to your advantage. It's like a wall- mostly clear. 

in the Farm Story, there was a glass wall, writing the story of the CBers. I suppose that is also a way of putting the Mystery. 

Currently, there aren't a lot of ski lodges that implement the mystery that have been finished- check out Lake Lellilo, the Farm Story, both by Mice, or a more recent one, completed in my 5 or so months of on the CB, by Luna, and it's called Magicae Palace. 

Please don't hesitate to reply if you'd like more details. 

I bid you au revoir, 

NightSky, Notorious Shipper and Magnificent Insane One 

Hello! I don't know much about the Mystery (I think I've read Lake Lelillo, but it was a while ago), so refer to other people's advice on that subject. I would like to point out, however, that you don't need to include it in your ski lodge, and there are many ski lodges that don't.

From what I understand, the Mystery is a pretty meta concept. It's based on the existence of ski lodges that don't probe it. And even those that do involve it do so to varying degrees; so you could just mention it in passing without making it a large part of your plot.

Obviously if you want to include it, go for it! But if you don't fully
understand it or it seems like an obstacle, you can always write a ski
lodge without mentioning the Mystery at all. I've written... at least
one ski lodge... (staying mysterious) that didn't include the Mystery (mostly because I
didn't know about it myself), and it turned out pretty well, if I do say
so myself.

I don't know much about it but I think it's mostly been covered . . .

In my mind, at least, there is no one set of rules for all Ski Lodges. Just what typically happens in them. So don't feel chained down to include the Mystery and ake sure it works like in all other Ski Lodges -- it'll be "there" in a sense no matter what, but don't feel the need to make it and your ski lodge exactly like the others. 

Is there a ski lodge that explains how the Mystery gets restored after Lake Lelillo?

Thank you all for the information! I will utilize it, I can tell you that. My ski lodge is open on PP, now, too!