It was undeniable how the young surgeon was gaining pleasure through inflicted pain and the girl's struggles, the girl's muffles screams. Even in the night, there were certain shifts that were notable, though notations then gained a sense of certainty when Sebastian leaned in to lick her. There was no guilt from stopping him thereafter, just as there was no possibility of quickly dropping his hand. The firm grip would be persistent and Mathis would not be deterred as anger turned onto him. Ill reactions were a commonality in the medical examiner's work - as an agent, that is - so he could easily observe them without batting an eye. He might have acted swiftly and held on strongly, but there was no change of demeanor beyond that. He met the boy's gaze coolly, the usual sense of being unimpressed in place though he was also disappointed, as he was still intrigued. It was a delightful contrast but the decision was made and it would be stood firmly by.
A wrist was almost like a neck. It did not have an abundance of organs, but there was still bloodflow and still a pulse point to feel. There was also the possibility of real harm if he facilitated the whole limb extending from the wrist. There would not be the same, beautiful and horrible display as cutting the carotid artery, but drawing a blade along the forearm would give him a point where he could milk the life out of him. Yet Mathis was not on the attack. He was a rather still point again, observing the missing pin and then the boy who once held it. The anger rolled off him as yet another disorganized point. Sebastian did not possess reign over his emotions. He was like a dog, growling over his scraps, and a such a misbehaving animal was truly meant to be beaten. The surgeon pulled and complained, but Mathis remained firm, denying him, maintaining his control. He would not be evaded and Sebastian would find he could not twist free.
The control itself was pleasing for him. It always was when he had an advantage and a significant portion of intel over all others. His undercover assignment, for example, put him in the most peculiar position of deceiving everyone but there was no minding it, especially since he was not a man who sought out connection or familiarity, who did not give out courtesy or friendship as a standard. The further out of reach people were, the more he could observe them without upsetting any sort of balance and the more he himself could remain uncompromised. Holding onto the boy before him was a direct contradiction of that, but the absolute control it gave him was its own thrill. Thus he was not done; he was far from done, especially as Sebastian transitioned into a nuisance with his venomous speech and struggling. Mathis appreciated complacency far more, so in the briefest instant, he slipped his hand back to grasp the boy's hand instead, and in a subtle wrenching action, given the joint's small size, he twisted it backwards. The action placed a tremendous amount of painful pressure on the wrist as it locked, but Mathis continued. He drew his hand back so the elbow and shoulder would twist as well and used the quick progression to compromise the boys balance before he knocked his feet out from beneath him. It was only when Sebastian was on his knees that he paused again. He still held him in the contorted wrist lock with one hand, ready to add more pressure if he tried moving, while the other hand returned the ciggy to his lips so he could take a drag.
"You," he said pointedly to the girl, his voice a command that could not be ignored. "are dismissed." He then eyed the young surgeon as though he was not sure what to do with him next. "You will not be released. Your time for play has ended."