I can't remember much else but I do know that it ended with Thor finding out his true heritage. I think there was an appearance by the Warriors three at this point..
If anyone knows what this fic is, it'd be much appreciated thanks!
Edit: I also just remembered a few important scenes. When Loki is all grown-up, he gives Thor a marking on his hand to prove that Thor is under his protection. Later, when Thor has gone back to Asgard, he keeps the marking and then gives Loki his own marking from Asgard. Which kinda forges a peace treaty between the two races as both of their princes (rulers?) are linked.