Magic, coed?, Dalton fic search

[liveshows mania]

Hey! I read this one fanfiction some time ago and can't find it. I remember that Kurt had a 'vision' that he was in a darkish room (which later revealed to be like a basement..). Everything mainly happened in Dalton. There were these 2 siblings, a guy and a girl. The guy had powers that could like calm people down. Kurt met him in a library. His friends tell him to stay away from him. He is also the reason he woke up in this dungeon/ basement at school.
Thank you in advance xx
New so sorry about tags.