Heartbeat by D.N. Hoxa

To Morta Fox, a twenty-year-old girl living alone outside the Wall of Protection, waking up with a craving for blood is something she never imagined could happen. To make matters even worse, a vampire who calls himself Hammer takes away her last attempt at self-destruction.

Hammer has been chasing Everard – the vampire last seen with his missing mate – for a year. Right before he finds him, he witnesses a girl jump off the tenth floor of a building. Though her bones break, she heals just as fast. When she stands up, she runs as fast as only vampires can. But she can’t possibly be one, because…she has a beating heart.

When Hammer saves Morta against her will, she’s furious. Until he proposes a deal. If Morta agrees to help him find her Lord Everard, Hammer will, in return, kill her. It’s a simple deal. They even make a promise, and in the vampire world, promises cannot be broken.