The Smartest/Dumbest Hostage

You spit in the bum's general direction, but your aim is off and it lands harmlessly on the sidewalk. The homeless guy isn't too impressed with your act, but he says nothing. You continue to walk, with your back turned to the bum. You feel a prick in your back and then a sharp seering pain. The bum just shanked you. You turn around and laugh at him. He looks frightened, but you have been through so much worse that this pain feels like a minor bee sting. You take the bums hand and squirm up to his pointer finger. He looks at you with confusion and fear. You brace his arm and punch towards his forearm. SNAP! The mans finger breaks and his bone is protruding awkwardly from his hand, with his skin handing limply around his destroyed finger. He looks at you and screams in agony. But you arent done yet. You take his arm and bring it over your shoulder. Another snap. You drop your weight and pull down on his arm with all your might. His elbow snaps backwards and twists at the same time. He screams again. In the dark, and in this city, screams are a regular thing to hear in the night, even if you can't remember it. You then twist his arm up into a brutal arm bar. You push up hard on his elbow and his shoulder lets out a loud 'POP'. He passes out on the ground and you walk away. You realize you were good at hand to hand combat, but now, since it is the only thing you know about yourself, it becomes your obsession.