I may have posted this before... sorry if it is a duplicate. I looked but didn't see it:
Inspired by "An Unearthly Child"
by Anthony Coburn
College student PCs (or Faculty) are in a tutorial program for special kids. One child seems to be a genius and is studying some advanced curriculum at college levels though at a young age. It is becoming apparent the child is letting out little bits of knowledge seemingly teaching the PCs little by little. However some basics of education and life everyone takes for granted the child is oblivious too like currency, dates and times of famous events and so forth perhaps insists on mathematical concepts never heard of. Sometimes the child seems alien, mysterious and cold, stares vacantly... generally creeping people out.
The child is the spawn or incarnate of a forgotten god and actually lives in Metropolis. Making his/her way through a slum or industrial area of the city. If looked into it will be discovered to be a fake address. Try to peak PCs interest... to find out all they can about this girl/guy and follow her. Several records can be suspicious or faked on the child... arousing PC curiosity.
The child can be unaware of his/her identity... PCs can be led into Metropolis. Having discovered the child's secret PCs have opened a can of worms. Maybe a servant of the forgotten god threatens them, the schools director/dean is really a Lictor... the child has caught his attention and he might seemingly cooperate with PCs to get information... looking to use this somehow to his advantage or protect the Illusion...
The forgotten god may have or will awaken from the activity and have taken an interest in humanity being trapped or it's existence. The incarnate is a way to learn about humanity for some dark purpose. Meanwhile the Lictor wants to use PCs to help him somehow get control over this entity or eliminate PCs who know too much... needs some work.