After begging the Doctor to take them to the fair, with no adventures, he finally gave in.
"You've never been to a fair before?!" Rose exclaimed.
"Why would I?"
Rose grabbed his hand and pulled him forcefully. "We're gonna take you on some rides."
The Doctor finally opened up and had fun on the rides with Rose, but he refused to get on the Ferris wheel. Rose bought him cotton candy and he wouldn't eat it before examining it closely and scanning it thoroughly with the sonic screwdriver. She refused to take no for an answer and forced him onto the Ferris wheel.
"Something horrible always happens and we'll get stuck at the very top!" he argued.
"You watch too much TV."
"I don't watch TV!"
"Then you haven't lived enough."
"I've lived nine hundred years!"
"And never gone on a Ferris wheel? I don't think so. Besides, what are you doing scared of a Ferris wheel? You can fly, for crying out loud!"
The Doctor was tense for most of the ride, waiting for something horrible to happen. It never did and he eventually relaxed.
They walked back to the TARDIS as the sky darkened.
"That was fun, wasn't it, Doctor?" Rose asked.
The Doctor didn't respond.
"Doctor?" Rose said, turning.
The Doctor was gone. She spotted him sprinting away.
"Doctor!" she ran after him.
He jumped into the air and pumped his arms, chasing a kid who was crying and running away. He flapped his arms and flew over the kid's head, rising above the crowds. Rose noticed what he was after: a balloon. He reached out and caught its string and swerved back to the ground. The kid looked up at him in awe as he landed and handed the balloon over.
The Doctor strode back to Rose as if nothing had happened. Rose grinned at him.
"What?" he asked.
"You'd run across the universe just to reunite a kid with his balloon, wouldn't you?"
"Well . . . he lost his balloon and I can fly. It's no big deal."
"No, it isn't. And that's what makes it so big."
They returned to the TARDIS and it faded away, unnoticed.