Imma make this as simple as I can 5 months ago stiles disappeared from beacon hills without a trace after the fiasco with donovan. 1 month ago stiles returned to beacon hills with Scott's dad and he was no longer the weak sarcastic spaz they once knew. When stiles doesn't tell anyone what happened to him while he was away Scott goes to deaton for help. That's when the pack are consumed in a white light and wake up surrounded by people they don't know to watch videos about one stiles stilinski. Or Stiles disappeared 5 months ago when an evil organisation called WCKD kidnapped him and wiped his memories 5 times. And he winds up in a movie theatre with all the people of his past to watch videos about his life. Yay him. - under editing but still being updated -

When Stiles disappeared after his argument with Scott, the pack searched for weeks, and months even before they slowly started to lose hope in ever seeing their friend again. Meanwhile, Thomas was fighting for his life in an epic battle against WICKED which they won but not without a few casualties. After living months in the Safe Haven, they're rescued by the FBI. Thomas and fellow gladers return to Beacon Hills, having no memory of their lives before the Glade. When Scott and the pack realize Stiles is back in town, Scott tries his best to reconnect with Stiles. He wants his best friend back, the same sarcastic goofball who he's known since the 3rd grade. But instead, he's met with someone who he doesn't recognize, someone different, someone new. He's not the same person he was when he first disappeared. He's not Stiles Stilinski anymore. He's Thomas, leader of the Gladers. Discontinued...sorry :(