Y/N and Loki grew up inseparable. They were always together, and trying to tear them apart was not a good idea. But being the Goddess of Thunder meant Y/N had missions, and Y/N had to leave for a mission to save the Nine Realms. And she also had to leave her brother, Loki. She expected to return to find things the same, but everything was different. Loki was gone. Not dead, but disappeared. Odin refused to talk about it, and banned anyone from going to find him. Especially Y/N. Because everyone knows she'll do anything for her brother, even break her own father's rules. Y/N spent months sneaking onto Earth through the Bifrost, but she never found anything useful. Every path was a dead end that somehow still led her to believe Loki had something to do with it. There were whispers about a man with a scepter. Rumors that he could create illusions with his bare hands. But that sounded nothing like the sweet brother Y/N knew. She mostly ignored it, but the words infiltrated her mind. Still, she chose to do nothing of it except look for him. Until it was too late. It was an ordinary day for her. Sneak through the Bifrost to search Earth, and most likely come hone empty handed. But when she arrived in New York, it was chaos. Chitauri soldiers were flooding out pf a portal in the middle of the sky, the place was reeking of destruction, and standing on top of the Stark Tower was Loki. Her brother. Now, Y/N must face the fact that her brother has changed from the sweet boy to the king of chaos. And she must find a way to bring him home. Even if it means teaming up with Earth's 'Avengers'.