So here's a little idea I had the other day: We all know about Celestia's School for Gifted Unicorns, but there are also two other Canterlot schools which bear her royal name: Celestia's School for Pegasi Prodigies, and Celestia's School for Advanced Earth Ponies. The latter of these is attended by Maud, beginning about two years before NMM's return. While there she comes across a most peculiar statue, made of a strange stone which defies her abilities to identify. One day it looks like marble yet has qualities like pumice, another day it appears to be sandstone but acts like obsidian. She takes an interest in this strange rock and sets out to discover its secrets.

And that's all I could decide on before I hit too many crossroads. This could go a variety of ways in a variety of genres such as:

Romance: The statue (since we all know any vaguely named statue in a pony fic is actually Discord) is touched that someone is actually taking an interest after all these centuries and starts to fall for her, subtly changing into rarer or more unique materials to keep her interest. She begins to suspect the rocks sentience and a strange bond is formed. And maybe we have a somewhat different sort of chaos when he gets out. (Plus the possibility of a great Pinkie one-liner "Wow! My sister would love what he's done with the... everything.")

Adventure: Maybe it's not Discord, but a relic of his from centuries lost, and Maud has to travel on an epic journey to an ancient civilization to discover the secrets of the stone, gathering a ragtag band of strange ponies and creatures as friends as she goes.

HiE: The rock is boulder and there's a human spirit trapped inside it. She actually can communicate with Maud through subtle vibrations. Plenty of well-trodden paths to take this one down.

See? All sorts of possibilities for this idea! Here's hoping someone takes an interest.