A/N: Rated K and pretty angsty but with my trademark happy ending, promise!

"This is it, isn't it?"

Molly's words, so quietly spoken, nevertheless reverberated through Sherlock's mind like the loudest of shouts.

The sigh that followed her words - and his lack of immediate response - stabbed him just as painfully through the heart. Metaphorically speaking and quite literally as well. "Right, then. That's settled. I'll just...get my things and go. Give me a few days to find a place to board Toby, if you don't mind? Just, um, feed him, I've cleaned the litterbox recently so that shouldn't be a problem. If it takes longer than a few days I'll see if I can bring him to John's, or maybe Mrs. Hudson won't mind if I keep him in 221C, or…"

"Don't go."

As soon as the words left his mouth, Sherlock knew he meant them. He reached out, grasping Molly gently by the arms. "Don't go," he repeated softly. "I was wrong, and I'm sorry."

Molly gave his face a searching gaze. Of all his loved ones - and she was, oh, she was very much loved, he needed to tell her that more often, obviously - she was the one who could read him best. Almost as good as Mary - no, don't go there, Sherlock, stay in the moment. Focused on the 'now' as the saying went.

Focused on the living, breathing woman still looking up at him. Judging him, and rightfully so. He'd said many things in the past to get his own way, and he just hoped she could tell he wasn't doing that now. Not this time, not when so much hung in the balance.

Not when it was their future he'd almost certainly destroyed with those cutting words, voiced out of frustration with himself rather than her, carelessly spoken but instantly, deeply regretted.

"Why not?" she finally asked. But she hadn't pulled out of his grasp, hadn't moved away from him, and he took that as a hopeful sign.

"Because I love you," he replied. "Because I was angry and frustrated with a case and lashed out at you without thinking about what I was saying. It isn't true, any of it. You're not keeping me from figuring it out, that's all on me."

"I don't ask a lot of you, Sherlock," Molly replied quietly. He nodded; that was and always had been true. "But I'm going to ask you to promise me that you'll never do that to me again. I'm not John; I can't let hurtful comments just roll off my back with a shrug and a 'oh, that's just how Sherlock is,' do you understand me?"

He nodded. He did. Completely. "I do," he replied, sliding his hands down her arms and taking her small, capable hands in his. "I prom-"

Molly shook her head. "Don't promise unless you can keep that promise," she said fiercely. "I won't be spoken to like that, Sherlock, not by you or anyone. I won't be belittled or dismissed or made to feel like a burden. Not even - no, especially not - by you."

"I promise." He said the words firmly, without hesitation. He was a man who seldom made vows, partially because such things were ridiculously easy to break and therefore meaningless, but he made this one wholeheartedly. "You'll never hear such hateful words from my lips ever again, Molly. I promise."

She gave him another searching look, then nodded. "All right. I'll stay."

The unspoken "for now" was understood by them both.

Thirty years later, as they sat hand-in-hand admiring the sunset over the beehives in the back of their little honey-colored cottage on the Sussex Downs, he turned to her with a soft, reminiscent smile. "I never forgot that promise, Molly. The only one I ever made you until our wedding vows. And I never will."

She leaned over to meet him in a sweet kiss. "I know, darling," she murmured with a smile. "Love you."

"Love you, too."

He meant those words as well, and always had.