I've read or listened to many of Ms. Kleypas' historical romances, and they always make me feel happy by the end. I think it's partially because they were so "proper" in that time and so prudish. Then, when they couldn't bear it anymore, they'd let all their passion loose.
Tasia has escaped a death sentence in Russia for a murder she doesn't remember committing. She's run to her cousin in England, and that cousin's husband has placed her as a governess with a friend whose wife died. Lucas is a somewhat cold man, believing he'll never truly love again, though he does take advantage of mistresses for his baser male needs. But once Tasia comes into his life and challenges him as if she's not simply a servant, he can't get her out of his mind. The fact that he knows she's not who she says she is intrigues him that much more.
I thought their budding relationship was very sweet. I almost wondered if we were going to get a taste of dominance in Victorian times, because often times Lucas acted incredibly dominant, and Tasia bloomed under his attentions. But of course, she was running from her life in Russia, and of course it caught up with her.
All worked out, and considering all the arranged, loveless marriages of that era, it always warms my heart when a couple actually falls in love.