GuardianAngel, my sincere apologies for not responding earlier to your wonderful comment. Thank you for that insight - I agree with you that this was a tipping point in their relationship. In Beth's mind, either they really made a go of things, or she was gonna stop trying. And by grabbing her and physically stopping her from escaping his grasp, Mick established not just his determination to try to make the relationship work... he also made a clear, vampire-style declaration that Beth was HIS woman. And that he would fight for her. (Even if the person he had to fight was Beth herself!)
I've never thought that was a romantic kiss. I described it in another story as "World War III," and from Mick's point of view I think that's what it was. It was a fight. And he won. But the way he won was to surrender to his feelings for Beth. Because it wasn't just a physical struggle: the physical struggle reflected a mental struggle with himself. Mick had to acknowledge that Beth was his woman. He had to surrender to love.
I've been thinking a lot about the end of Sonata, too... and I think I understand why Beth said "I don't think I can do this anymore." Mick asked for time, but after that passionate kiss and that admission, he retreated, big-time. There were no more kisses, no serious discussions, no advancements made in their relationship, for weeks. Beth tried to give him space, because he'd asked for that. But he wouldn't let her in: not emotionally, not intellectually, not physically. He kept all the vampire secrets from her, and he wouldn't even court her properly. Beth made a huge commitment to Mick at the end of Click, but Mick never even knew about it. And the experience with Jacob must have brought back so many terrible memories for her... she was already on emotional thin ice. And then, with all the traumas that took place during Sonata, I think Beth just lost the will to keep beating on that wall Mick had built around himself. So she sent him away. And Mick realized that the kiss had only been a small first step - he needed to say the words out loud, to himself as well as to Beth.
"I love you." We all know that when they closed the door to Beth's apartment and Moonlight ended, Mick and Beth hadn't solved all their problems. They didn't go on into "happily ever after." But they were moving into "together, through thick and thin." And that's the only way to make a real relationship work.
Jenna, thank you for that lovely comment. I do think that this was the beginning of Beth's true understanding and acceptance of Mick. The
whole Mick. If he had followed up on the promise of that kiss, if he'd begun to court her, and to help her understand more about his vampire world, she would have been more prepared for the things that happened in Sonata, and they might not have had that shattering conversation where she sent him away. But then again, our lovers never have been that good at talking about the really important stuff till there's a crisis.

So maybe Mick needed that horrible moment in the hall, with his head against the wall, to force him to go back in there and tell her what they both needed to hear.
