Fate Changes That Day

Because of certain events and a sudden change in Kiritsugu Emiya, the Holy Grail War that should have taken place never happens. Rin Tohsaka grows up safely under her parents' care, then goes to study at the Clock Tower. During her studies, she learns that a new Holy Grail War is about to begin. After speaking with Tokiomi Tohsaka, Rin decides to take part in it so she can discover why the Holy Grail War that should have taken place in Fuyuki City never happened...

(The setting is fairly complete, and the story aims to be as plausible as possible. Any major changes will generally be pointed out. Of course, there are bound to be some bugs, so please bear with them.)