The Doctor and Rose were wandering down the streets of a small town sometime in the future when a young girl of no more than twelve came running up to them.
"I know you," she told them bluntly.
The Doctor squat down in front of her, his coat flapping out around him to land in a puff of dust on the dirt road. "Is that right then?"
Rose looked at the Doctor, who was smiling with amusement. Obviously this had happened to him in the past.
Ah, right. The past. Realization dawned on her. This girl must have seen or heard of them from one of their previous trips. The hazards of hopping back and forth in time, she supposed. You never know when you'll be recognized.
"Wait right here."
The girl took off running and came back minutes later holding a slightly worn paperback book. Rose took it and began to read the summary on the back, then burst out laughing. When the Doctor asked what it was that it said she just looked at him and started laughing again.
"What?" The Doctor asked more insistently. Rose calmed herself down and began to read.
"Rose Tyler and The Doctor, intergalactic lovers-" At that she broke again, resuming her full on laughter. She handed the book off to the Doctor and began to walk away. He quickly caught up with her and she began giggling again.
"I know you find this endlessly amusing," he said, his voice dripping with sarcasm, "but there's just one thing before we go."
"She wants your autograph."