The Doctor watched, a small smile playing over his lips, as Rose watched the crowd pulsing around them in the busy London square, absently eating chips from a basket in front of her.

"They'll be by in a minute or so," he said. She looked at him across the table, her expression holding excitement and worry.

"You're sure they won't see us?" she asked. "I mean, it could be problematic if we triggered their memories or something." She shuddered delicately. "Had enough threats of paradoxes the last time we ran into them."

"I promise," the Doctor said calmly. "I remember today, visiting twentieth-century London with Charley, saving the day when some aliens try to steal all the art from the National Gallery…" He smiled reminiscently. "Even the terrible pieces, the silly things."

Rose smiled. "We should leave as soon as we see them, or else you'll be tempted to get involved with that even though you're already taking care of it as him."

The Doctor laughed. "No, I promised you an easy day, and that you'll get." He kissed her cheek. "Starting with chips and a check-in with my old self and Charley, because I know you've been thinking about them."

"I just want to see they're all right," she said, scanning the crowd once more.

The Doctor smiled. That was his Rose, always worrying for everyone. It wasn't enough that she was home and happy, she needed to know that it had worked out the same for Charley. Well, he thought, he was the one with the time machine and a Time Lord's memory. He'd picked a place and day where he and Rose could blend in with a crowd and see his previous self and Charley without being seen themselves. It was a relatively simple task, and he would do – and had done – far more than that to make Rose happy.

He watched her watch the crowd, and could tell the moment she caught sight of Charley and his other self. A smile spread across her face, bright as the sun.

"They look happy," she said, watching them fondly.

The Doctor glanced over at them, remembering how he had felt walking down the busy London street hand in hand with Charley, looking forward to a quiet afternoon in the National Gallery. He smiled. "They are."

He shifted his gaze to Rose, took her hands across the table, nudging aside the half-eaten basket of chips. She took a last look at the retreating couple and then met the Doctor's eyes. "And so am I," he said seriously, wishing he had the words to explain to her how lost he'd been with her gone, how much better he felt with her back where she belonged. "So very happy."

Rose squeezed his hands. "Me too," she said. Then, mischievous twinkle in her eyes, she dropped one of his hands, grabbed one of the chips, and popped it in her mouth. "These chips are fantastic."