Wild at Heart

From the author's website:
They called him "the lost man." He was beautiful, wild. Raised by wolves, without speech, without civilization. And when he was captured and locked in a room to be studied by scientists, he was treated more like an animal than a human being.

Only Sydney, daughter of a renowned anthropologist, saw beyond the wildness to the man. Something in his fierce loneliness called to her, imploring her to help him -- to save him. Fascinated, drawn by compassion and then desire, Sydney used gentleness to tame him, patience to educate him, kindness to make him her friend. And he would need a friend, for the world was not nearly so understanding, and his new life was still haunted by the mysterious tragedy of his past.

But now he wanted more from her than friendship. He wanted all of her -- her love, her heart, and her soul.