Intro. Great! Here is a possible beginning for the story:
Primordial Instinct
The first time Logan saw Anna, he knew he was lost.
It was not just a desire, it was not just attraction. It was something deeper, more primitive - an instinct that roared within it like a beast waking from a deep sleep. He tried to ignore, tried to convince himself that it was just a passing impression. But then the second time came. The third. And each meeting only fed the hunger inside it.
Anna had no idea what aroused in him. She smiled at him as if he were just one more in her world. The casual touch of his hand on his arm burned like a brand on his skin. His smell invaded his senses and pervaded his mind. He began to realize patterns - the way she bit her lip when she was concentrated, as she played with the necklace when she was nervous, the exact moment of the day when her perfume became stronger because she retouched before leaving.
Logan hated himself for knowing