Rather than call Isaac inside, Derek walked to the door and opened it himself.
He'd been pacing, anyway, his body tense with frustration. Stiles' fault. He'd gone to the boy's cabin intent on learning the truth, wanting answers that Isaac's vague description hadn't given. Wanting satisfaction, only to be completely unsatisfied. Angered.
He hauled Isaac against him, rough, as he claimed the boy's mouth, hungry and desperate for release, for the satisfaction he couldn't get from Stiles. He would get it from Isaac, in his perfect slave's perfect obedience.