You Don't Know Me Scott McCall

Stiles knew things were different between him and the pack ever since the Nigistune. But he never imagined that Scott, his brother, would take Theo's word over his.

Believing Theo's false information about Stiles killing Donovan in cold blood, Scott kicks Stiles out of the pack.

Not knowing the true reason why the scrawny human was kicked out, the pack had come up with a few ideas of why.
"He's weak."
"He's a defenseless human."
"We can't keep protecting him."

Stiles begins to understand that he's not wanted within the pack. Not even by Malia, his own girlfriend. Being neglected and pushed aside far too many times, Stiles leaves Beacon Hills, and ventures forth to prove to his former pack that he's not just a weak defenseless human.

And if he ever returned to Beacon Hills, he'd make them regret ever kicking him out in the first place.