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It was like the entire universe ground to a halt. Full stop, brain switching to power save mode, press any button to continue. Nothing moved. He didn't even breathe.
Strictly speaking of course, he didn't need to breathe. It was one of those things that he did so that Rose would be less alarmed by how starkly different his physiology was from hers—it was the little things, he noticed, that set her off. Take her to the destruction of her home planet, she laughs it off, but forget to inhale and she's off sobbing somewhere—but the momentary halt in respiration was for a completely different reason. The common human metaphor, said the part of his brain that was completely comprised of books, is that your "breath was taken away." Your respirative abilities aren't impaired of course, it continued, but it's supposed to signify—
The Doctor cut himself off mentally, with a quick "yes of course, I understand." The fact that he was having a lively conversation with himself did not seem at all strange.
She had come to the bottom of the stairs, dressed in clothes a bit late for the period, but the Doctor wouldn't complain. She had swept her hair, a little messily, into a bun, and donned a green—and—black velvet dress with striped stockings and black leather shoes that were a little worn. And her face, good Lord, was grinning hugely; a child wanting to be praised for dressing properly. At once he saw her a thousand times; Rose Tyler of the present, Rose Tyler laughing in the bar with her mates, Rose Tyler unwrapping a red bicycle at age twelve and shrieking in delight.
"You alright?" she asked. The Doctor nodded quickly, forcing himself to inhale harshly through the nose.
"Fine, sorry. Just thinkin'." He said. She smiled again, as though she knew what he was thinking. It made him feel exceedingly awkward. Power save mode off, universe returning to full speed.
"What about?" her question was intoned softly, but coquettishly. Something in her eyes glimmered with an impish look that she'd seen reserved for Mickey alone. Her lips curved temptingly, and all at once, he was struck with the maddening realisation that she knew exactly what she was doing.
"Are you holding your breath, Doctor?" she asked. His eyes bugged hugely from his skull, and he inhaled again.