Sarah Jane Smith wrapped her hands around her mug of tea and tucked her feet up beneath her on the couch, staring out her living room window into the silent night. In the stillness she could detect the low hum of K9 at her feet, a sound she'd never expected to hear again. What an incredible 48 hours this had been.

She had promised herself earlier today that she would no longer dwell in the past. She'd promised herself that, this time, she would move on with her life – and it was a promise she was determined to keep. But tonight, this one night only, she would allow herself the luxury of looking back. One final time.

Twice now, meeting the Doctor had changed her life.

The first time had been like passing her days in shades of grey and then suddenly step-ping into a world of brilliant, vibrant color. It had been a marvelous adventure, full of wonder and magic and punctuated by moments of terrifying danger that had only served to heighten the vivid intensity of the experience.

This second time had been so bittersweet.

Bittersweet. What an aptly defining word that was, she thought. So inexpressibly sweet. And so unexpectedly bitter.

She recalled the electric shock of recognition that had jolted her upon stumbling on the TARDIS, parked so innocently at the back of the school gym. She'd backed away in dis-belief, turned – and then she saw him. And she knew. Even before he said her name, she knew.

It was amazing, really, that she hadn't known before, when they first met in the teachers lounge. There had been something about the surprise in his eyes, and the look of dazed amazement on his face. And 'John Smith' – really, could it have been any more obvious? But he'd died. After all this time she thought he must have died.

Seeing him alive – even now, the reminder of it brought a soaring, ecstatic happiness to her heart. He'd been real, and solid, and she could almost taste the fierce joy she'd felt at simply being with him again, if only for the briefest time. He'd taken her hand, and it had been as though the years had melted away in the giddy exuberance of running once more by his side. The sweetness of knowing he was safe and near had been…incredible.

But with the sweet came pouring in the bitter. All those times they'd been together and she thought he'd died, he'd always somehow managed to come back to her. But then he left her that final time, in Croydon that was really Aberdeen, and never came back. For thirty years she'd grieved for him – for them. How dare he be alive, and leave her all alone?

'You were my life.' Sarah grimaced. She'd said so much more than she intended – had it startled out of her by the acid bitterness she felt. He'd sounded so cavalier at having left her behind that she couldn't stop herself from lashing out, to punish him for his failure to realize – or to care – and she'd ended up sounding like a silly schoolgirl. Or a forsaken lover. Once again she'd forgotten how alien he was.

He said he couldn't come back for her. She wished with all her heart she understood why. Was it the Time Lords? Had they forbidden it? But he'd said, 'Everyone died.' And Mr. Finch had offered the Doctor the chance to save his people – a chance that, at the time, had sorely tempted him. Something terrible had happened on Gallifrey. Was it this that had prevented him returning, or something more personal? She shook her head, vexed. Still so many questions.

Maybe…she tried immediately to bury the thought, but the lonesome, empty silence of the night refused to let it lie. In the darkness it whispered in her mind.

Maybe he hadn't wanted her any more.

He found, after all, a newer model – Rose Tyler. Brave, generous-hearted Rose. A young woman so much like Sarah Jane herself at that age that she almost had to laugh. There would have been no reason at all why he would have come back for her this Christmas just past, she reflected, not when he already had someone so courageous and quick-witted at his side. Most likely, his inviting her back aboard the TARDIS earlier today had been nothing more than a token attempt to make things up to her for leaving her behind all those years ago.

He'd never even mentioned her name. Try as she might to deny it to herself, Rose's catty comment had cut her to the quick. Worse still, he apparently hadn't even noticed – it didn't seem to have occurred to him until Rose brought it up. She knew she hadn't been the first human woman to travel with him, as his earlier self had mistaken her for more than one past companion. Was she the only one he didn't care about, or need? The mere possibility of it tore at her heart so viciously she had to close her eyes against the pain.

And yet, she knew it wasn't so. Hadn't he comforted her after she thought she'd lost K9, lost the last thing she had of him, of her Doctor? Hadn't he told her goodbye, a word he hated, understanding her well enough to recognize how much she needed to hear it? And as he did, he'd swept her up off her feet and into a crushing embrace…and looked into her eyes with such affection, affection he would never speak aloud but for once was written on his face as clearly as a shout.

As for herself, the truth was she'd always loved him. Had never stopped – could never stop – loving him. His essence was imprinted on her soul. She'd meant what she said to Rose, that the Doctor was worth a broken heart.

Tonight, that broken heart was finally mending. The Krillitane's offer to the Doctor had been a forceful reminder that all relationships had their time, that not even a Time Lord could turn the clock back on them once they'd gone. With that realization, her love for him ceased to be an anchor that bound her inextricably to the past and at long last, she allowed herself to let go.

So tonight, she would rejoice that now no longer would the least reminder of the Doctor be accompanied by a searing pain in her heart. And that for the rest of her life, when she heard his voice in her dreams, she would awaken with a feeling of warmth and gladness instead of an aching sense of emptiness and loss.

She was so glad she'd finally had the opportunity to thank him for their time together. He'd shown her so much, and given her so much. And long after she had lived out her small life on her small planet in the infinite vastness of the universe he would go on, carrying her in his hearts. In that way, at least, she would always be with him. The thought was a comfort. One final gift from her Doctor.

And even if he never spoke of her again, he would never forget. She knew now he would never forget.

'My Sarah Jane.'