Sabrina Crane was a well-known doctor at a clinic where "medical miracles" were known to constantly happen. What people didn't know was that Sabrina was responsible for those miracles.
Sabrina is a Vampire, the name given to people who are victims of a very rare genetic anomaly. Being a vampire is both a blessing and a curse. Vampires have an insatiable appetite for blood, but their bite is cleansing: if someone has their blood drunk by a vampire and survives, that person is cured from almost any illness. This is no easy feat, as most vampires drink mindlessly once they sink their teeth into someone. Any vampire that hasn't been hunted has learned to drink from blood packs to avoid accidental killings.
Sabrina learned to drink without killing when she was a child, when she attacked her brother and managed to stop herself before killing him. She decided to try to help people and became a doctor. She spent long hours finding the patients she believed needed her healing the most, sneaking into their hospital rooms when they were unconscious to cure them. However, one day a nurse caught her drinking a patient's blood, and she was forced to go into hiding or risk facing the harsh justice dealt to vampires.
Now she runs an underground clinic, continuing her cause to help people--as well as getting enough blood to live off of by accepting annual blood payments from her patients.
For the Twilight of the Vampires contest at Seventh Sanctum [link]