As soon as the light flashed through the windows of the London townhouse, The Doctor felt the weight of his decision to save Adelaide Brooke crushing down on his hearts. It had been a mistake to tell her how he had changed things. He should have let her live her life in peace, never compromising the future that would never be by telling the astronaut captain about the inspiration that Adelaide's death inspired her granddaughter's own journey into the stars. Now, despite all of his work to ensure the headstrong female's survival, a hole was left in history where another brilliant mind could have flourished and grown. So much for the Time Lord Victorious; maybe Adelaide had been right to tell him he was wrong. He couldn't control everything and he knew that because he had preached the same thing over and over again to the people he travelled with. He remembered one such conversation with Rose back on the Game Station, oh so very long ago. He'd told her that it was wrong to tamper with the laws of time and that nobody should ever have that much power. He had even cost himself yet another life by saving her mind from Bad Wolf. He had become a hypocrite, reflecting everything he despised back at himself. It had been the Time Lords' stubbornness and pride thathad caused the destruction of Gallifrey during the Time War and he had fought hard to try and prevent that disaster but here he was making the same mistakes that he had tried to correct during that time. He was a traitor to his own cause and that fact was burning in his mind as he walked back to the TARDIS, head bowed in sorrow as he mourned the loss of Captain Adelaide Brooke.
Just as he reached his hand out to grasp the handle of the wooden door that would lead him into the warmth of his ship, he heard a voice; the only voice that could ever soothe the bloodthirsty creature that resided deep within his soul. "Doctor." the voice called out, soft and yet strong but filled with sorrow, as if there was some knowledge residing in it that he did not yet know. Turning in the direction of the sound, his eyes widened as they fell upon the form of the blonde female he had lost so long ago. "This is it, isn't it?" he asked gruffly, his tone deepened with the grief he felt at his very core. The blonde didn't reply verbally but she nodded solemnly, otherwise standing completely still as she watched him from her place in the center of the snow-covered London street. The Doctor's deep brown eyes cast down to the ground with the revalation that his worst fear had come correct and that he really was going to die once more; another incarnation gone with the wind like down from a thistle. He contemplated for a moment before looking back up to Rose, fearing for a moment that she would disappear the moment he stopped looking at her. In spite of his anxieties, there she stood, as beautiful as ever as her hear flowed around her head in the cold winter air. "I failed you again, didn't I? Threw away all the progress I made with you, just to satisfy my ego."
The blonde's brow furrowed with those words and he steeled himself as he waited to hear the cutting words that Rose had for him. "No." she replied simply. "Doctor, you know this isn't the end of anything. You can still be the man I fell in love with. You have all the time in the world to get it right. I'm not going to blame you for making a mistake and the fact that you think I would just proves how lost you are." The Time Lord's eyes brimmed with tears at his former companion's words and he sunk to his knees, not even flinching as the snow melted under him and seeped through his suit pants, chilling the skin that lay beneath. He knew she was right and yet he still felt an immense pain in his heart that he couldn't explain, like there was still something that needed to be said. It didn't elude him for long as he looked into Rose's eyes, the words coming to him instantly, as if they were waiting there for him in her gaze. "Will you still love me, even when I'm not the same man?" he asked as tears slid down his face, blurring his vision slightly as he tried to blink them away, not wanting to waste a single second that he could use to gaze at the form of Rose Marion Tyler. He knew how hard it had been for Rose to watch him regenerate the first time, never mind the anguish she had conveyed when the threat of him doing so again had come around when he was gunned down by that Dalek right in front of her. He had no idea whether or not he would still be himself after this next regeneration, just as he had never known before any of the others and so he was certain that Rose would say no. However, a breathy laugh emitted from the blonde female as she finally moved, stepping closer to the grief-stricken Time Lord and crouching down beside him in the snow. "You'll always be the same man and I'll always love you. You're The Doctor, my Doctor and, no matter what you look like or who you become next, there isn't a single power in the cosmos that would stop me loving you just as much as I do now."
It was that validation that got the ancient man to stand once more, holding onto the TARDIS to keep him upright as he kept his gaze fixed on the woman he loved. "Thank you." he said, stifling a sob as he tried his best to find the words he needed to convey how much he loved this beautiful human. "Thank you for coming back to me and for showing me time and time again that I can be more than what I was. You really did make me better and I promise I'll use every second to prove to you I can still be that man." He truly meant the words he said and, in his mind, they were the only words that mattered. However, when Rose shook her head, The Doctor knew his mistake. "You don't need to prove it to me. I'm not really here. The only person you need to prove it to is yourself. Be a hero, be a madman..." she cut herself off abruptly as a single tear rolled down her face before she smiled sadly at him and continued. "...be The Doctor."
With those three words, her form evaporated into the blackness of night and Rose was gone. Slowly, The Doctor turned his back on the quiet London street and pushed open the door to his ship, entering silently and closing the door behind him. Out in the stillness of night, everything was quiet except for the sound of the TARDIS engines echoing and fading as the Time Lord and his ship dematerialised, leaving the Earth once more for the enveloping embrace of the Time Vortex. There were any things that the anicent Gallifreyan was uncertain of but now he had a newfound sense of hope that things could still get better. It didn't matter to him that he was about to die. All he needed, all he had ever needed, was the knowledge that Rose still loved him. He knew he had hallucinated the whole interaction but, even then, it was enough. She was always enough.