Again, inspired from a tumblr prompt.

This is set after Midnight

Lullaby (Doctor/Donna)

The blank look in his eyes had terrified her. She'd seen those eyes wide with surprise, squinting with mirth, bulging with rage. But it was the vacant emptiness that scared her to her core. It made her want to hunt down whatever that thing was and destroy it all over again.

But now, he needed her. He'd deny it, but she knew he needed someone to guide him and take charge. Even if for just a little while. She'd taken him back to the TARDIS and demanded he rest. He'd protested. She knew he would. He'd said he didn't need sleep, so she had countered and said to just find a quiet place and let her be. He'd disappeared, and Donna had been in the kitchen, making some dinner and trying to think of some place peaceful for their next destination.

Donna checked the clock in the kitchen. It had been two hours. Smirking to herself, she was satisfied that she'd been right. Still, the unfamiliar quiet of the TARDIS felt a little odd.

She didn't know where he'd gone off to. Hopefully to his room, and she had no interest in going there, thank you. Grabbing some cookies and pouring a warm cup of cocoa, Donna wandered over to the library.

Stopping short as entered, she found where her Spaceman had chosen to rest. Sprawled out on the beat-up red couch, the Doctor was so still in his slumber. Donna stared down at him, marveling how young a nine-hundred-year-old being could look.

Glancing around, she clicked her tongue at the mess around her. While she knew she was in danger of violating her own directive that he sleep, she didn't want to leave. Something was keeping her in the room with him; whether it was for his comfort or her assurance, she didn't want to dwell on. Donna started to gather the various books and knick-knacks, from who-knows-where-or-when. Absently, she hummed a soft melody as she worked. She had half a mind to start dusting too, and when she turned to see a cloth and some cleaning solution, she gave the walls a cynical smirk.

"Guess again, honey," she whispered before resuming her reorganizing, humming once again.

A soft moan silenced her. She paused and looked over. The Doctor was still sleeping; he'd turned over a little and grabbed at the blanket.

Regretting the possibility that she had disturbed him, she gathered her food and started to dash out of the room.

"Don't go."

His voice was soft, but it sounded light, happy. More like him.

Donna turned and saw a pair of brown eyes gazing at her with their usual intensity. It was such a welcome sight; she had to catch her breath.

"Sorry," she muttered. "I didn't mean to wake you." She turned to leave again.

"No, wait, Donna!" he called again as he sat up. "That was nice."

"What was nice?"

"The humming," he said. "That was a pretty tune."

Her checks colored a little. "Oh…yeah."

He sat up my fully and waved for her to come back in. Obliging, Donna settled on a chair across from him. "I've never heard it before," he said. "What's it called?"

Embarrassed, Donna's smile was small. "It was just some silly thing my dad used to hum while he was working around the house. It would get stuck in my head for hours when I was a kid. I think he made it up."

Donna looked over to see him smiling at her. "That's a lovely memory, Donna," he said softly.

Her throat unexpectedly tight, Donna nodded.

He continued to watch her. "And you have a very pretty voice."

That was too much. "Okay," she said, standing up.

He smiled sadly and threw his palms into the air. "Okay, I'll stop," he conceded.

Pursing her lips, Donna walked over and sat on the edge of the couch. He leaned back, still looking tired. She flipped a few strands of hair from his forehead. His eyes had not left her since she'd told her story.

As her fingers danced through his hair, she saw some color return to his cheeks.

"Feeling more like yourself now?" she asked.

He nodded. Donna leaned over and kissed his forehead. Maybe she lingered longer than she should have, but she wanted to assure him that she would always be there for him. When she pulled back, his countenance was completely at ease.

"I'll let you rest up some more," she said, standing.

As she gathered her things, a low sound joined the TARDIS's song. She turned and looked at the Doctor, tears distorting her vision. He was staring at the ceiling and humming her father's tune.

When he'd finished, he turned and straightened in alarm when he saw the stricken look on her face. "I'm sorry!"

She laughed tightly. "It's okay," she stammered. "It's just been a while since I heard it from someone else. Even my mum stopped when he died."

The Doctor held out his arm. With no hesitation, she returned to him and rested in his light embrace. They sat quietly, letting their thoughts drift along with the TARDIS's steady drone.

"Donna?" he asked after a moment.

"Yeah?"

"Thanks."

She turned and smiled, happy he'd let her comfort him. "Sure, Spaceman."

Headcanon: Eleven and Twelve (etc.) still hum that tune.