Birthright

What if....Loki never went to the dungeons. What if... Frigga convinced Odin to send him back to Midgard. The Loki that arrived back, though, had no memory of Asgard. No memory of 2012 and certainly no desire to rule.

He lived a new, quiet life. Always feeling different. Always slightly unfulfilled.

Now, in this alternate timeline, Thor desperately needs him to help fight the end of Asgard. He sends a Valkyrie to retrieve him. Convince him who he is and to come back. That Valkyrie had one job. And it wasn't to fall in love. But she did.