Story Idea -- The Ghost Library

The story that I'm about to run will involve the characters encountering an unusual study source: A library that exists, frozen in time, only in the memory of it's ghostly librarian.

The library is set in a burnt-out winter covenant that had fallen years ago. Through a series of long ago tribunal politics, the reason for the fall was covered up, and the covenant site fell out of the general knowledge. The characters are now exploring the ruins, and will come upon the burnt out library. After crossing a barrier, they will find the library magically restored in all it's glory: They have stepped into a magical regio generated by the ghost of the Bonisagus who ran the library. The ghostly bonisagus lives in a memory loop: Studying an ancient text, muttering to himself and taking notes. At some point during the day, he is attacked by the traitors who brought down the covenant, and the room is set aflame. He perishes trying put out the flames and trying to fend off his attackers. This traumatic episode transforms him into a ghost.

The goal of this scene is for the characters to end the loop, and turn the room into a study source. In particular, a specific text that will lead to a future story.
I'm thinking that if the characters can defeat the attackers, then they will have the librarian to speak to, and the memories of certain texts will be available to them. (Probably at low quality, as the memory can only hold so much of the text....)

A) does this encounter generally hold to the game's understanding of how ghosts work? This feels a little more like a faerie episode since it's a "story loop", but I can't figure out the game logic of how a magical library in a magical aura would turn into a faerie aura /episode.
B) If this is within the general game rules regarding ghosts, then are there any other / more interesting ways to end the loop than destroying the memories of the invaders and putting out the ghostly flames?
C) Are the ghostly invaders -- consisting of the ghost librarian's memories only -- mentem in substance, or are they imaginem? Does it matter? Is the most important thing to convince the ghost that the invaders are defeated?

Any help is welcome as I puzzle this story out within the logic of our Most Favorite Game. :slight_smile:

Upon reading the "Magic Spirits" chapter of RoP:M, I think I have my answers.

The Ghost Librarian has several powers:
Presence -- The Library
Regio -- The first layer is entering the library, finding the librarian muttering to himself. After striking up a conversation, two attackers enter and set fire to the library. Defeating the ghost attackers is the key to the 2nd layer of the Regio, wherein one can study the texts in peace.
Eidilon x3 -- The ghost himself is one form, the two attackers are the other two forms. -- And this answers my question that the ghosts are Imaginem, not Mentem.
Material Anchor -- the main lab text that the Librarian has written. This the apparation's key to "moving on": Once a character studies it, the Librarian can move on to the afterlife, because his knowledge has been passed on.

I think this will work for the story. Am I missing anything?

Regarding the Ghost Library as a source of information, you can also consider that the Ghost is a teacher, with a certain Com+Teaching score. He can teach one topic (skill or Art) per season, to one or more "pupils".
Since he is a Bonisagus, calling on his great knowledge to be passed on as a way to be remembered, it won't be too difficult to convince him to obliged.
By the way, it has the small advantage that you only need to consider the Ghost Com+Teaching, and the knowledge in various Arts & Skills instead of having Quality, Level for all Summae & tractatus.

You can also use that as a way to remove this resources when you feel it filled its purpose: the ghost knows he has past enough knowledge to be remembered and can finally depart.
The information he absolutely needs to pass could be the information needed for your next story. The ghost cannot articulate that it is what binds him here, but he might try to hint, or lead to some topics close to this key info:
"I am surprised that magi like you are not more expert in ...."
"In my time, XXXX was considered part of the curriculum for anybody who would call himself a master in YYYY"
"The history of this Tribunal/region/kingdom is fascinating, and myself used it to uncover a couple of valuable artifact such as this wonderful silver cup, which is unfortunately now only a figment of my imagination <as a magus'hand goes through>."

Only once the PCs ask the info and fully understand it can he rest.

Ah, good call! I like the idea that of using his com+teaching instead of the Quality/Level of the Summae. That's neat. I will probably do that for the "important" stuff that he knows/remembers. The other books would have low quality because he doesn't quite remember them or find them important... Can't hand EVERYTHING to the players! I'll probably do this visually: The important books' pages will glow brighter, etc, because they are more vivid in his memory.

Exactly. Yup!