You are a young vampire that works to help people in a hospital. You are always by Dr Sathier's side and he helps to take care of you after your parents threw you out for what you are. You go around helping patients with blood levels and they are typically perfectly accurate. The patient always consents to it and you do it as gently as you can for this kind of thing.

This morning was like any other. You were sitting in his office, reading a book when he comes in

"Hey River, Someone wants you do test their blood"