For one shining moment, towing the Earth on the back of his beautiful ship, he'd forgotten that it was never meant to last. They'd always leave him, in the end, from broken hearts or exhaustion or something nameless and deep and irreversible. Why would he think that day would be different? The sounds of laughter and joy reverberated through the console room, sounds that would not be heard for long after they left. His most precious people. His family, as Sarah Jane had put it, the one he had needed for so long and ended up gathering together without him realizing it. All gone. The only sound the Doctor could hear was that of his own worn-out trainers against the metal grates of the TARDIS floor, echoing in the stillness with no one to answer them.

His recent journeys with Donna had made him realize that his life had turned into a child's nursery rhyme meant to teach a cautionary lesson; every person he let close to his hearts seemed to serve as another test of whom he'd become since the War, since the darkness. He had resisted for so long against thinking that people – that human beings – could teach him anything, until those human beings ('stupid apes', his previous self would affectionately insult them) had forced themselves into his life, made him see the universe with new eyes.

Hundreds of years later, standing alone in the stars as the last of his kind, it took those silly little humans to make him realize the universe was still as wonderful and mysterious as before, still waiting for him to stride in and own the place, his companion by his side. So many had passed through his TARDIS; so few ever stayed for any length of time.

He loved Rose, of that there was no doubt. She was golden hair and sweet smiles and laughter, with a curiosity and adventurous side that was so welcome after the war. The Doctor had spent time after the burning of Gallifrey by himself, stumbling around aimlessly in a new body that was already broken by blood and flames; he couldn't even stand to look at himself post-regeneration until several years later, looking into a mirror at Powell Estate, wondering why his ears were so blasted big. Rose had literally swung her way into his life, and once he realized he was falling for her, he fell hard. After the incident at Bad Wolf Bay, saying goodbye across the uncrossable void without so much as a last farewell hug, he thought their paths would never cross again.

So it hurt more the second time – hurt to see her walk away from him with his mirror image, destined to live out the rest of her life with a man with one heart in a world with zeppelins and no blue boxes that were bigger on the inside. It hurt in a good way, because she could finally be happy – but without him, without the life they'd made together.

Just as she had opened up the heart of the TARDIS to save his life, Rose Tyler had opened his own self up to the realization that it was okay to live, to walk away from the scorched earth of Gallifrey. And if Rose taught him it was okay to live, Martha Jones taught him it was okay to love. After losing Rose Tyler too soon after he realized how much she truly loved him, he'd closed himself off to the idea of letting a companion get so close to him again. Even when the runaway bride told her he needed someone, the idea didn't stick until brilliant, confident Martha Jones walked into his life, someone who was used to taking care of those around her, and he didn't realize how good she was until it was too late.

And it really was too late; by the time the Doctor could see Martha for the woman she was, she was halfway out the door, ready to take care of her trauma-stricken family and new love. He could have easily loved her so deeply and so soundly, this confident beautiful woman, if only his hearts and eyes had been opened in time. To see her happy again years later, a ring on her hand and a life of her own yet totally willing to fight in his name once more, set his insides aching all over again at all the lost chances. She truly was a star, Miss Jones.

Martha Jones had done so much for him; she had watched after him in 1912 while surrounded by hostility and racism, walked the Earth while he languished in the Valiant as a captive, been his guiding spirit when he'd been possessed by a dangerous sun that could have burned them all. Hell, she had even gotten a job at a shop for him, like she wasn't one of the most brilliant medical minds in her class. He never got to say "thank you" to Martha, not directly and not in so many words, so he did the next best thing: he brought back fiery Miss Donna Noble, super temp of Chiswick. He almost never went back for companions after so long, but Donna Noble was a lesson in second chances, and the Doctor wasn't about to let her slip away.

She was loud and bold as brass, with no filter on her mouth and no limit to her incredible, well, assets (you couldn't blame the man for noticing she had a gorgeous body most Time Ladies would regenerate for). She pushed the Doctor into doing things he wouldn't normally do as well as held him back when he teetered on the edge of going too far, and he pushed Miss Noble into realizing that she was amazing and so full of greatness, even if her mum couldn't see it. Donna became his backbone, his indomitable spirit, his best mate. And yet, sometime after the library and River Song and the holiday resort gone wrong, the Doctor realized he didn't want to be Donna's mate. He wanted her to be with him, forever, as much of 'forever' as a human being could stand.

And then she was gone, lost forever. No, she had not disappeared beyond the void, but she was just as untouchable. She had not gone off on a new life fantastic, but she was just as distant and unknowable. Donna Noble – the woman the Doctor had laughed with in Agatha Christie's garden and listened to the song of the Ood with and slowly, surprisingly, fallen in love with – was lost, hidden underneath layers of wiped memories that could never be broken through lest he lose the woman forever. And it was all his fault.

The Doctor slumped against the doorway leading into the sprawling corridors and endless chambers of the TARDIS, feeling his hearts constrict a little at the raw memories rushing through his mind. Images played through his subconscious in vivid colors, taunting him with how real they felt. There was Donna, standing outside the TARDIS, hat boxes everywhere; the energetic grin on her face could power a small city. There was Donna, wrapped up in purple and speaking Latin with a smirk, then later looking him straight in the eye, asking him to save someone, anyone from the ash fall of Pompeii. Donna brilliantly pointing out the kinks in ATMOS' bureaucracy, Donna walking through the snowy drifts of the Ood-Sphere with her red hair blowing around her face, Donna relaxing by the pool on the surface of Midnight and looking like a queen in her terrycloth robe. Lovely, lively Donna who could never remember a thing.

No, it was never meant to last. Perhaps that was the true curse of the Time Lords; his two hearts meant he loved more deeply with every human that crossed his path and hurt ever so severely when those sparks of life left his world forever. Never had this suspicion been more acutely felt since he regenerated for the eighth time and met the three women who had so deeply changed him overall. One had brought him back to life only to become lost to him twice, a woman of gold and sorrow. Another had loved him until she could no longer stand by his side in silence, a woman of sorrow and mirth. The last had become his best mate and shield against his own oncoming storm only to lose it all and her own self in the process for the man she considered her best friend, a woman made of secrets she was never meant to be told of again. He had started out at his journey a war-scarred man all by himself who could trust no one and couldn't see the value of his own life; he'd come out of it with a different face, a different pair of hearts touched by so many hands, yet still alone.

The man was exhausted from all of the running and the rain that was probably still falling on the place his TARDIS once stood only moments ago, now hanging in the limbo of space waiting for a destination. Normally, he would be setting random co-ordinates right now, letting his precious machine rip through the vortex toward another location where he could lose himself but this last adventure of his had near drained him both physically and mentally. If there was any day to sleep it off, it would be today.

On his way to his bedroom (or really anywhere that didn't still feel haunted by them) he lingered by the console for a moment, tracing certain controls with the tips of his fingers. The co-ordinates for certain moments in time and space burned in his memory. New New York, year 5,000,000,023. Royal Hope Hospital, year 2008. Eddison Manor, year 1926. He was a man who had held the strands of humanity's narratives in his hands more than once, always meaning to do good. It would be for good, too, if he were to go back and see them one last time, wouldn't it? For them as well as him - look, I'm still here, no need to worry! Got both hands and feet, nice long limbs all intact, so you don't need to wonder if I survive our latest little dance around danger 'cause I'm from the future, y'see?

Right. As if Rose, Martha, or Donna would believe him in the sorry state he was currently in, his left shoelace untied, his jacket sloppily closed and his tie loose from being wrangled around a bit after everyone's departure. They knew him too well. And now they'd be the last to know him so intimately. They were part of a world that was closed off to him now, where the people that made up his voluntary family lived and loved and functioned without him but still remembered him fondly as the man from the stars that brought them all together.

It was a place he could never go back to, for the sake of all of them - the Doctor and his precious friends. Rose. Martha. Donna. And the others - Sarah Jane, Mickey, Jack, everyone. He could have taken Sarah Jane on one more trip, given Jack one last dance, finally told Mickey that he wasn't just another tin dog. They lay beyond his grasp, having said their goodbyes in one way or another, all going back to their lives or beginning new ones. It was beautiful and terrible, letting go of his children, but it was not a new phenomena. This sharpening pain in his chest, however, was as new as ever.

The only thing he wanted to do was sleep forever; the last of the Time Lords, in a place where not even his memories could reach him. The last time he had felt this way, he was burnt and wrapped in leather and had the hair of a soldier and the blood of an entire race fresh on his hands. The problem was that he couldn't. He won't allow himself to. The Doctor always goes on, through war and loss and suffering, whether he wants to or not.

A trail of dropped clothes followed him through the corridor: a tie undone at the doorway, a jacket hung sloppily on a random wall hook helpfully provided by his last companion, sneakers awkwardly kicked off into a corner to be abandoned. The lights of the TARDIS blinked off as they followed his path until they found him all curled up, legs drawn up to his chest like a humanoid roly-poly, in the comfiest chair in the library. One arm was strewn lazily across a nearby end table where his paperback copy of Death in the Clouds still sat, a paper bookmark sticking out from where Donna had left off in her reading.

The lights in the library were the last to turn off, leaving its lone inhabitant to sit in the soft darkness with only the constant hum of the TARDIS to keep him company. The Doctor closed his eyes and for the first time in years, his thoughts did not instantly drift off to the burnt skies and silver leaves of Gallifrey but to the constellations hanging around Earth, as seen through a TARDIS' viewer screen while surrounded by the brightest stars in the universe.