The Doctor sat on the sofa in the TARDIS library, feet propped up on the table, reading the same paragraph he had started reading many minutes earlier. He was trying not to notice that Donna was sitting very close to him, her feet also propped up on the table, as she flipped through a magazine. He thought she was sitting rather closer to him than normal, but surely that was his imagination.

"Doctor?"

"Hmm?" he replied, looking up from his book at her. Had she moved even closer? He couldn't be sure.

"Do you trust me?"

"Of course I do," he answered quickly. "Er, why?"

She leaned across him to reach the bowl of popcorn on the table. He thought he did a very good job of not noticing that her blouse was unbuttoned a bit more than usual, and that she brushed against him just a little more than was strictly necessary. Not that he minded, he just didn't want to get slapped today.

"Oh, just thinking," she said, tossing her hair over her shoulder.

"Er, are you feeling alright?" he asked. He really must check the climate controls in this room. He was sure it was getting warmer. He tugged at his tie to loosen it. He saw her eyes follow his movement, and he swallowed.

"Oh, I'm fine," she said. She leaned down again, picking up her glass and taking a sip. She licked her lips as she set the glass down, and he cleared his throat nervously. She looked back at him. "Are you alright?" she asked, eyebrows raised.

"Fine, I'm fine," he said.

She crossed one leg over the other, shifting closer to him as she did so. "Just getting comfortable," she said, patting his leg. She flipped a few more pages in her magazine, so he returned to his book. He read the same paragraph over a few more times, trying to control his thoughts. He tugged at his tie again. Donna looked at him sidelong through her lashes. "Sure you're alright?" she asked.

"Never better, nothing wrong at all," he said. He turned the page of his book. He tried not to notice the scent of her shampoo as she pushed her hair behind her ear. He moved his feet off of the table.

Donna leaned down to put her magazine on the table, then turned toward him, her arm on the back of the sofa not quite touching his shoulders. "Doctor," she said again.

"Yes?" he said.

"I have a theory I'd like to test, and I need your help."

"A theory?"

"Yes, a theory. I'd like to test."

"About what?"

"Well, it's sort of personal."

"You can tell me anything, you know that," he said.

"What if you don't like it?" she asked.

"I can't imagine not liking anything about you," he said. She had moved her arm as she slid even closer to him, their knees touching.

"Okay," she said.

"Okay," he repeated. "Fire away."

She didn't say anything, just leaned toward him, one hand moving to rest on his chest.

"What are you doing?" he said, pulling slightly away. Surely she wasn't doing what he thought she was doing.

She stopped, and he could feel her breath on his cheek. "I told you, testing a theory. Now shut up," she said, and she kissed him. Her lips were warm and soft on his, and she opened her mouth so he could explore with his tongue. He could taste the salt from the popcorn, the sweetness of the tea, and her. He realized his hands were still holding the book he had been reading, and he tossed it aside so he could cup the back of her head with one hand, the other hand at her waist. Too soon, she pulled back, her eyes sparkling, her lips red.

"Well?" he asked, his voice squeaking. He cleared his throat again. "Well, what was the theory?"

"That you were a good kisser," she said. "Without the anchovies and ginger beer."

He grinned. "And, was the theory confirmed?"

"Oh, I think I need a lot more data," she said.

"Well, don't let me stand in the way of scientific progress," he replied, as her lips met his again.