Immortal (Immortal #1)

The wound inflicted only a few minutes before was nearly healed. A small cut was the only sign that anything had occurred. I watched in disbelief as it finished closing and eventually disappeared.
“What are you?”
* * *
Gods, demons, and vampires… Eighteen-year-old Alina Taylor doesn’t believe in any of them. Then, she meets Samuel Grant and Duncan Michaels and discovers a world that could destroy everything she loves.

First book in the Immortal Trilogy.