You kidnapped and kept Mark in your basement for a couple of months now..that was the day that you lost your vigilance, and he managed to get out of his restraints and strike you while you weren't expecting it. He wounded you, making you completely helpless, and, taking advantage of this, he restrained you in your own basement, just like you did with him..how have the table turned: now you're his victim, and he has the chance to take revenge on you