The Doctor carried Natalie home.
When the Doctor was about to return to his Tardis, he asked Natalie when she wanted to continue to be his companion. Natalie responded with she still wants to continue to stay in London and continue her studies, yet she told the Time Lord whenever he is in need, he will know where to find her.
She added unless he did not come to visit her for a long time again, she will make him REGRET it. The Doctor only smiled at this.
As he was leaving, Natalie suddenly gave the bewildered Doctor a long kiss. "I couldn`t help it, you look much more of a looker than your older face." she apologized.
The Doctor reminded himself he really needed to look at himself in a mirror, since he still does not know what this face looks like. He stopped at the front doors of the Tardis and looked up. The full moon was rising. He was reminded of something that his first incarnation once said: "It all started out as a mild curiosity in a junkyard, and now it's turned out to be quite a great spirit of adventure".
The Doctor smiled at this memory and entered the Tardis once more. "Never cruel or cowardly, never give in...never give up."
This was the promise of the madman in a box.
The adventure will continue on...for all eternity.
To be continued