Because that is definitely not something Derek would ever wear, Stiles thinks, when he sees the velvet, red cloth jacket and tight pants. There’s a necklace dangling from his neck and the gem on it is a deep purple with swirling patterns inside the stone. The cut of his hair is too neat and he looks tired.
“You’re not Derek,” Stiles says, suddenly much more awake than he had been before.
Or, the one where Derek has a twin that appears out of thin air, and they have to find him a way back to the past.