The mad space wanderer who seemed to dwell in a blue box; he was nothing more than a fairytale among the children of Asgard. They knew him as a good-hearted but fearsome figure: “Go to bed, or the mad space wanderer will find you and take you away in his blue box!” Some children dreamed of being whisked away, some were terrified. Thor had been neither of this, because he, unlike them, had actually met the space wanderer.
"Doctor," he said his name to himself with a smile. As he stood at the edge of the Bifrost, looking out at the stars, he spied the blue box hovering harmlessly some distance away. He wished that he could follow the Doctor to wherever he went; the wanderer had told him of so many places, so many impossible adventures, enough to fuel the imaginations of a young boy and made him long to have those adventures themselves.
"In time, young ones," the Doctor had told him with a laugh. "You’ll have those adventures, no doubt. Earth and everything in between. In the future. And you will have the best and most loyal of friends." He had grinned at both him and Loki, but Thor was too young at that time to notice the faltered grin when it had come to his brother. "Yes… in time. Don’t you worry."
The blue box was nearly out of sight now. Thor knew that if he called out to him, the Doctor would answer, but he let him pass. He wasn’t a boy anymore now. He was the heir to the throne of Asgard. He had his responsibilities. But he would never stop believing in him, the mad space wanderer.