It was quiet in the TARDIS control room.. Clara was off in her own room, sleeping. The Doctor understood the human physiological need for sleep on an intellectual level. He also knew from practical experience that humans became downright surly if they didn't get enough rest or were awakened early or abruptly. So he took advantage of the solitude to do a bit of a tune up on the library computer. Every so often, he'd check the sensors that monitored Clara's room. He needed to know that she was safe, even if she was out of his sight.

"It's all right, you know. You don't have to do that."

"Do what?" he asked, carefully not looking up from the console. He could just make out her reflection in the monitor. The red shawl from their adventure in Victorian London was draped around her shoulders, and her usual impish grin was replaced with a rather more serious expression.

"Check up on me all the time. I'm here. I'm fine. I'm not going anywhere, and nothing's going to happen to me."

"You don't know that, Clara," he replied slowly.

"But I do know you. I know, for an absolute fact, that if there was anything you could have done to save me, you would have."

"So instead, you saved me."

"And I'd do it again." Clara came up beside the Doctor and rested her cheek against his arm. "I don't blame you for anything, so stop blaming yourself."

The Doctor sighed and wrapped both arms around her. "I don't know what I'd do if I lost you again."

"You'd find me," Clara replied confidently.

"I'm beginning to think we'd find each other," the Doctor replied slowly.

Clara's eyes sparkled mischievously. "Now you're catching on, Chin Boy."

"Chin Boy? Chin Boy?" the Doctor spluttered. "What's wrong with my chin?"

Clara giggled at his exaggerated expression of outrage.

"It's not funny!"

"Yes, it is! A ten thousand year old man, sulking about his chin."

"I am not ten thousand years old! And I am not sulking!"

"What d'you call it, then?"

"I - you - shut up!"

Clara was still laughing too much to speak quite clearly. "All right, truce…you stop trying to wrap me in cotton wool, and I solemnly promise to stop teasing you about greatly exaggerated facial features."

"Greatly exaggerated…!" He still looked comically affronted.

Clara stretched up on her toes and lightly kissed the end of this chin.

"Oh, all right," the Doctor muttered, rather petulantly, but Clara could see the gleam in his eye, and the way his mouth quirked up at the corner.

"What've you been doing to that library computer?" Clara asked curiously.

"Oh, I've just been…hey…how'd you know I was working on the library computer?" he asked suspiciously.

"Because I've hacked into the TARDIS's sensors so that I can keep tabs on you, too," Clara replied with a wink.