He knew why he was doing this.
Well of course he did, it was his reward.
No. It was so much more.
For Mickey and Martha, it was a thank you. For all those times they had stood and taken the blunt end of his fury. For the days they felt like tin dogs, useless and unappreciated. Saving them, like they saved him? It was the least he could do. The expressions of understanding and pain so distinct on their faces made it all worthwhile. They knew he was going to die. Them knowing that, them understanding that he would not be coming back…. It hurt. So much. He had so much he wanted to do, so much he wanted to say. In the end, he had given it all up for those he loved. Didn't he always, though? He owed them this comfort. He would die knowing that he was remembered. That made it so much easier.
When he threw Luke, the son of Sarah Jane, out of the way of the oncoming car, it was a debt. She had been so kind to him, bringing youth to him when no one else could. Yet, she had always needed someone to lean on. Now she had a son, a smart, intelligent son. No doubt, remembering him. He might take himself from her, but not her son. Seeing her, how she smiled so uncertainly, it made him feel so young again. Memories of them were enough to get him by. She knew. She always knew. Her eyes shone with unshed tears. His Sarah Jane, who's song would end even sooner than his. May the angels carry her to heaven, she disserved as much.
With Jack, it was a mixture of things. Pity, for all that he had lost. The man who could not die, suffering in silence. The death of a child, a lover, and a grandchild. More than anyone, the Doctor understood that. He had suffered all of that and so much more. The prices we pay, they can kill us more than any threats. The other part was gratitude. Jack had always been a comic relief in the Doctor's tumultuous life. No one but Jack could flirt while the world crashed down upon him. For that, the Doctor was forever grateful. So to him, he gave Alonso. Another war ridden soul to comfort him. The salute that Jack had given him, that last gesture of admiration, he would carry that with him until the end.
For Joan's granddaughter, it was an apology. For all that was, and all that could never be. The middle age matron had been so kind to him. The human John Smith had fallen for her quickly. Humans and their need to love…. It had always mystified him. 900 years of time and space, and the Doctor still couldn't understand it. She looked just like her grandmother. Blue eyes sparkling with wisdom, it made him stronger. Was she happy? He had asked that, letting the emotion fall into his words. Were you? Oh yes, oh yes. Happier than ever before. His last two lives had been filled with love, friendship, happiness, and sorrows. For the first time in 900 years, he felt so human.
Seeing Donna's wedding was just so he could feel content. He had started his life without…. Rose…. With ruining Donna's wedding. Now he could feel as though he had made a circle. Anyways, what kind of person would he be if he didn't see his best friend's wedding? Seeing her, laughing, in that white dress (without pockets, he reminded himself wryly) was an uplifting sight indeed. Surrounded by friends and family, normal, just as it should be. She could go on now, have a life, be loved. Slowly, she would forget about aliens and oddity completely. Though this thought pained him as much as his death did, it also made him smile. She wouldn't change. Wilf and Slyvia were so thankful to him, even more so when they realized that he had given them the winning lottery ticket. They knew as well. That it would be the last time they would ever see him. That he was dying. Funny, having so many people know only made it more frightening. At least, now, he could know that Donna Noble, proud ginger, super-temp, his best friend was safe. Happy. Alive.
His last destination was inevitable. Deep in his heart, he knew he would. He had to see her. He just did. Because if he was going to die, he would do it with the image of her in his eyes. Then maybe, maybe, it would be easier. The only person in the universe that could save him and shatter him in the same breath, his Rose. Young, carefree, smiling Rose, the mere thought of her made his heart leap and break. He stuck to the shadows, careful not to interfere with timelines. She was so optimistic, so beautiful. Her hat askew and her jackets mismatched, comforting her mother. When she noticed him, her curious eyes dancing, he felt the bliss of a million men. Hearing her voice in response to his, as if nothing was wrong, it made him fall for her all over again. She held herself close, blocking the onslaught of wind and snow. One day, some day, she would have someone to embrace her, hold her hand. Not yet, no, it was much too early for that. But soon, soon she would meet a man who grabbed her hand and told her to run. They would never stop; all the running and hand holding. And, when fate came into play, they would be separated. Both would feel a loss of proportion unfathomable. Never could they truly be together, he understood as much. But now, on that snowy New Year's Eve in 2005, none of it had happened. The hope, though, that it would, that it could, oh it made dying seem so much less daunting. He would die happy.
He would give his last moments. To her. To the wonderful, magnificent her, his last breaths, all for her. Because he knew. He knew that he would have given up his life, the dangers and the excitement, all of that up. He would have torn down walls. But not this time. No, not this time, in his last minutes of existence. In his last moments, he would do the one thing he truly wanted to do.
He would make her smile.