This was inspired by a prompt on tumblr:

After you read horror stories you always crawl into my bed late at night, how many times have I told if you can't handle them then don't read them?

Irrational

The entire TARDIS library was brightly lit. The Doctor actually squinted a little in the artificial brilliance. There was a sort of vivid silence too, where he could hear his own breathing circulate through his lungs.

Sitting in the center of it all was Donna, her profile to him and not noticing that he was in the room. For all her attention was wrapped in the book in her hands. The Doctor smirked. Her eyes were wide, her mouth was drawn, and her cheeks, under the harsh lighting, were pale. If he scanned her with his sonic screwdriver, he would surely get an elevated heart rate and increased levels of adrenalin.

She was reading one of those horror novels again.

The Doctor grinned to himself; the books Donna preferred were of the fictional sort. Not that had anything against such tomes; he rather loved a good whodunit and always thought himself exceedingly clever when he'd worked out the mystery by the second or third chapter. But he could not quite find the same level of enjoyment of the horror novels that Donna found so enthralling.

Well, not of the books themselves, but he enjoyed the after effects of Donna reading those books.

The Doctor backed away, not wanting to startle her while she was in the throes of whatever horribly macabre unveiling she was discovering. He walked over to his bedroom, not at all tired but knowing by Donna's internal clock that "nighttime" was fast approaching. He cast a wordless glance up to the TARDIS walls at the pristine and clean sheets that covered the bed and the warm glass of tea waiting for him. His eyebrow arched at the sight of the second mug on the opposite side's nightstand. It seemed the TARDIS knew the nighttime routine all too well and encouraged it. Sweet girl.

Kicking off his trainers, he sat, still fully clothed in his brown pinstriped suit, folded his hands together, and waited. After what felt like an eternity, but was only a few minutes, he exhaled impatiently and reached over to grab one of his own books, a sixty-fourth century study of the changing constellations over the Brixbane systems.

He was about to get lost in that starry world when there was a slight noise on the other side of the door. He saw a shadow waver on the floor, and he smiled. "Yes?"

The door slowly opened, and a rather pale, wide-eyed and uncharacteristically muted Donna Noble appeared.

The Doctor closed his book. It was exactly as he'd expected, and yet he still felt a thrill at it. "Hello, Donna!"

She nodded at him. "Hey, Spaceman."

He knew what she was going to ask; this had started weeks ago, and he could not imagine a better conclusion to his evenings.

And yet, she hedged a little. "Do you think…"

He gestured to the large space next to him. "Just for company."

Donna nodded vehemently. "That's it."

He laced his fingers together. "Did you enjoy your book?"

She grimaced. "Some people are really warped!" she declared. "What kind of mind comes up with that kind of twisted…" Her face contorted even more. "…perversion!"

"Wellllll, it's been my experience that humanity can produce the greatest of minds, in all things good and…." He met her gaze. "In all things terrible."

She wrapped her arms around herself and gulped.

The Doctor's flickered to the empty side of the bed, knowing she'd accept, but still nervous she wouldn't.

She did.

As she walked over, her expression became caustic. "I'm not scared you know," she said.

"I never thought you would be."

"It's just a story."

"Yep. Not real at all."

She sat down, still looking a little green. The TARDIS lurched a little, and she gasped and grabbed for the nightstand to steady herself. The Doctor shot an admonishing glare at the walls which shimmered in response.

He studied her. "Why do you read that stuff if it just unsettles you?" he asked.

She glared at him and burrowed herself under the blanket, still a safe distance away from him. He loved that she didn't even need to ask anymore. It had become a ritual he'd found highly satisfying. "I dunno," she confessed. "A little adrenalin?"

"Oh, traveling through time and space isn't exciting enough?"

She laughed. "Yeah, maybe I'm bored, Spaceman!"

"Tomorrow, I can find a proper scary planet for us to go to."

She blanched. "You do that, and I'll clobber you!" she warned, and there wasn't a doubt in his mind that she would.

They remained silent for a moment, and the Doctor could see her breathing slow and her jitteriness start to subside. He smiled kindly, happy to provide some comfort to her. He didn't want to press his luck though and say as much. He was afraid she'd up and leave, and that made his own hearts flutter more than he cared to admit.

Donna reached over for her tea, not even questioning that it was there. The Doctor felt a little puff of serenity at the fact. That Donna was content to just be there with him. She turned to him. "How about some place with funny alien animals?" she suggested, her blue eyes becoming heavy.

"Alien animals?" he repeated.

"Yeah, like a two-headed horse or something fluffy with pink wool."

The Doctor shook his head as she exhaled slowly. She looked completely peaceful and at ease, and it made the Doctor smile. He liked being able to provide that kind of safety for her. He'd do anything within his power to make sure she always felt safe with him.

She gazed lazily over at him. "Maybe I should read a happier book," she mused.

He nodded. "Then you can sleep in your own bed for once?"

Her eyes widened. "I like it here," she confessed.

The Doctor grinned. "Me too," he said.

Donna rested her head against the backboard and closed closed her eyes, slowly letting the nervous energy leave her system. The Doctor kept his book open, but he hadn't read a word of it.

"Whatcha reading?" she asked.

He showed her the title, and she snorted, making him chuckle. "I could read it aloud and bore you to sleep," he offered.

Donna grinned. "I bet it takes two minutes," she said and pushed herself down. The Doctor adjusted his glasses up and started to read from the first chapter.

It took one minute before Donna's breathing became deep and regulated. The Doctor paused and turned to his friend. Ginger hair draped over her face and she was smiling. He sighed, and rested his head against the headboard, more content in that moment than he had been in a very long time.