The Reckoning (Vampire Romance)

Isabella Beckett is a top-level scientist on a mission — to study and then destroy vampires. So when Julien de Valsan falls into her clutches she wastes little time in tearing him apart to learn how he "ticks." She refuses to admit how wickedly beautiful he is and she certainly won't admit a certain attraction. She certainly doesn't expect Julien to escape and take her with him.
Julien plans to make Isabella pay for what she did to him — with her body. He won't rest until she's writhing, moaning his name.
Except neither Julien nor Isabella expect to have feelings for each other.
Together, they learn revenge isn't always sweet, it's dangerous.