“Yes,” Peter said, putting a hand between Stiles’ shoulder blades and shoving him so he stumbled forward a few feet. “He’s for you, Derek.”
“What?” Stiles yelped. Derek’s nose flared and one side of his mouth raised up in a feral grin. Stiles whirled around to look at Peter. “What the hell are you talking about?” he exclaimed. “This is not what I agreed to!”
Peter gave him an infuriatingly calm look. “You said, and I quote, ‘Mr. Hale, I will do anything for the money.’ You signed the papers. You got yourself into this. And now you are going to do what you promised to do.”
And so: Stiles, deep in Peter's debt, is offered up to Peter's nearly feral nephew in an effort to keep him going over the edge of madness.