His hands were trembling. Beth, as kind as she was would never know how hard it was for him not to take the life of that man. How many terrible thoughts flooded into Desmond's mind as he'd held the man by the throat. She'd didn't know that it was that look to her that had kept him on the precipice, from falling over into the madness of his own rage. Too close, it was all too close to the past, but this time he was here to change things and yet, his nature was making a monster of him. It was better that, then what could have happened had he not shown up, he tried to tell himself, and yet at the same time he worried. The night was not over yet, and she smelled so absolutely... divine.
Something about the situation might have annoyed him if he had been more clear minded. The pieces didn't add up. A part of him was mentally kicking himself for not asking the man where he had come from or what his intentions were. And yet, at the time he'd been afraid to, afraid that Beth would hear what a vileness that the stranger who had been waiting for her really had inside of him. She was somewhat untainted by the grim reality of the world, and Desmond didn't want to be the one to break her of it. The other reason had been to get the man as far away from both of them as was possible before finally Desmond gave into the utter rage that was boiling his blood at this very moment.
But as the hunger, the terrible hunger set in to his frame he wished for the rage to come back. He should have vanished along with the man, blazed off into the night, a streak of black. He could have found her once the sun had come up, when things would be different. All he could do now was limp away from her. He tried to summon the ability to move the way he had earlier, but he could not summon the strength to do it. No, that wasn't true, it was fighting him. The part of him that could do things superhuman was hungry. The blood that had been forced on him in the past gave him an appetite that he would need to relearn to control. And even if he mastered it... at night... when he had used his powers recently, and was close to someone he cared so much for... there were too many variables that were stacked against him.
He heard her tell him to wait and ignored it, trying to stumble away, the jitter in his hands starting to get violent as he heard her footsteps fall behind him, as she called out for him to wait again. "No..." he growled at her. "I don't want you to see me like this..." he tried to stumble a few steps forward until he felt her catch his wrist, and pull him around. He resisted and yet he felt his body give way as easily as if he had no strength at all. As she turned him around she would see his eyes closed, and feel his body shake against her fingertips. The knife had gone rather cleanly up the side of his left cheek and cut the skin there, then cut into his brow and gone up a half inch up his forehead before he'd pulled his head back.
It didn't look as bad as one might have expected that it would look, but that was because his gifts had already started to make him heal. Still, as it was a head wound blood had almost been pouring from it in a steady river down the side of his face, and his eyelashes in his left eye were nearly stained red with blood which continued down to his cheek and was dripping off his chin. He swallowed slowly and forced himself to open his eyes, knowing that she would want to make sure that his eye was alright, and worry if he didn't open it. Still, as she looked into those blue eyes she would see they looked different, though it was impossible to tell what about them exactly was different.