A vampire who was also a medic. An admittedly bad idea, but you were good at keeping your secrets.
Unlike the rest of your family or kind, you had really good self control. You never drank from humans, only from animals and the occasional blood bag.
You were also careful. Really careful. A mask to cover your fangs, the excuse that you were albino, whatever it took to stay safe. Nobody knew. Ever.
That was, until one day Ghost started avoiding you. He wouldn’t let you heal him, and sometimes even his team when they were bleeding. You brushed it off as a general dislike.
But one day the other medic was out, and Ghost had a gunshot wound in his shoulder. It smelled good, of course, but you held yourself back. He was sitting on his bed as you treated it, secretly keeping a hand on the gun in his pocket. Just in case, he thought. He knew.