My most faithful student
First, allow me to extend my most heartfelt sympathies. Even with as long as I've lived, I can only imagine how you must feel after such a shocking discovery.
That being said, you and I agree on a very important point: Restraining Gary Stu in your basement is most certainly "a bit excessive."
Please understand that I don't mean to belittle what you are going through. I simply seek to remind you, my student, that matters such as this have a procedure that generally must be followed. Feeling Gary has wronged you is one thing. Electing to imprison him within your own home is rather another.
I am willing to grant you likely suffered a minor lapse in your better judgment given the nature of your revelation. It has happened to far more experienced ponies than yourself. In fact, considering that the last time you uncovered suspicious activities of this magnitude it lead to the discovery of the imposter Cadence, part of me almost wishes to applaud your initiative. I am most definitely impressed that you elected to try and talk this matter out with Gary himself prior to contacting me.
Nevertheless, I must request you release Gary Stu from the basement.
(Twilight, I have no doubt that your jaw just dropped upon reading that. Please finish reading before you begin dictating your rebuttal to Spike.)
Innocent until proven guilty is the basis of Equestrian law, my dear student. It is one matter to show Gary had knowledge of events to come. It is quite another to prove that he took advantage of said knowledge for the sole purpose of stealing others' glory and defrauding ponies of admiration, thanks, and other rewards that should have gone to another. Even then there is difficulty in establishing exactly what laws he has broken (Though the moral bankruptcy of his character would certainly be apparent in that case.).
Granted, his attempts to flee when you confronted him about the situation do not paint him in the best light. Still we must act in the interests of justice and that means properly investigating your accusations.
At time of writing, I have sent a detachment of the Royal Guard to collect statements from yourself and Gary, as well as these "story disks" you and Spike discovered so that I may study them myself. While Gary Stu is not to remain detained in the basement, you are certainly under no obligations to permit him to stay at the library. In fact, given the situation, it might be best if he sought lodging elsewhere in Ponyville for the time being.
Once that is done I have an important task for you, my faithful student. From what you wrote it would seem yourself and your friends would be the greatest victims of Gary's actions. While I review the story disks and deliberate with Princess Luna on this matter, I ask that you inform your friends and fellow bearers of the Elements of Harmony about your discovery. As friends to both yourself and Mister Stu they deserve to be aware of what is going on.
Plus, any opinions or insight that they offer might be important in settling this case.
You are a smart, capable, and honest young mare, Twilight Sparkle. Whatever your feelings towards Mister Stu might be at the moment I trust that you will keep this situation contained to only the involved parties. Unless Gary Stu is proven beyond reasonable doubt to be a fraud it does nopony, least of all yourself, any favors to begin spreading stories about him. Make sure your friends are aware of this as well.
I am trusting you, Twilight Sparkle.
Your caring teacher,
Princess Celestia
P.S.
If you have completed that paper about your modifications to Haycartes' Method then I would, of course, greatly appreciate it being included with the disks.
P.P.S.
Not that I mean to pry, but why do you have a specimen research slab in your basement?
P.P.P.S.
Spike? You are right, Twilight and I both taught you better than to nose around in others' belongings. You have my (and I'm certain Twilight's) thanks this time since it lead to an important discovery. I am giving you an Official Royal Warning not to do it again, however. You are far too nice a dragon to fall into bad habits.
Sister,
It would seem the secret to Gary Stu's seemingly miraculous problem-solving abilities has been discovered.
I'm not yet certain if it's better or worse than some of the possibilities we discussed.
It will arrive from Ponyville shortly. We should meet over it as soon as possible.
Sincerely,
Celestia
Finally!
This conundrum has been driving me crazy. Especially given his lack of magic (And ergo lack of connection to Equestria's collective subconscious! Would that I could have just walked his dreams...).
Inform me as soon as it arrives. I have been looking for an excuse to leave Blueblood's company for an hour.
Luna