The TARDIS was in flight, but other than the noises the TARDIS itself was making, things were quiet. And when the Doctor was traveling with Donna, that level of silence was too much to ignore.

So, he vaulted over the railing and landed next to her, bumping her shoulder with his and wearing his best grin. When she didn't smile back, though, he dropped that but stayed with his shoulder touching hers. "You alright?"

"Yeah," she said in a tone he recognized too well because he used it himself all the time.

He bit his lip, then nodded to himself and jumped to his feet again, going to the console to look for… ah, yes. There it was.

"Donna, they're going to be fine," he said, turning the screen so she could see the message displayed there. He'd received it ages ago, before he even knew who Dean and Sam were, and he'd archived it for later, when he had more context for what was going on.

Maybe it made him vain, but he kept every one of the thank you notes that he'd ever gotten—because he felt sometimes that he did so much damage that he needed the reminder, every reminder he could, that he was capable of doing some good, too. And as was the nature of being a time traveler, sometimes, he got thank you notes for things he hadn't yet done. And that only made him more determined to find whoever it was that had needed his help and get them whatever they needed.

And there it was, written across the screen: Thanks for the help. -Dean

Donna gestured at the message. "You're going to have to connect the dots for me, spaceman. So he said 'thank you'. Nice of him, but…"

"This was sent from the year 5, 357,491,003," the Doctor explained, grinning steadily wider as he saw the realization cross Donna's face. "I don't know what that means for them, but sometime in their distant future – or maybe sooner than that—they're going to be light years away, billions of years in their own futures."

Donna's slow smile turned into a grin, and then, she reached over to slug the Doctor in the shoulder.

"Ow."

"Why didn't you tell me?" she demanded. "I've been all worked up, and you've just been letting it happen!"

"Because I didn't want—look, Donna, there are a few fixed points in time, and from what I just saw, those boys are headed toward one now. And I don't want to inter-"

"Yeah, yeah, noninterference of the Time Lords, blah blah blah—you still should have told me," Donna insisted with her hands on her hips.

"Alright," he said, smiling as he held up his hands in a conciliatory gesture. "Alright, you're right. I should have told you."

Donna glared at him for a good, long time until she finally let out a loud sigh and gestured with one hand toward the screen. "So, what else aren't you telling me, huh?"

The Doctor laughed. "Donna, this isn't a secret. You can't tell me you haven't kept letters and notes before."

Donna tried to keep looking angry—she really did—but slowly, almost without her permission, a smile started to stretch across her face, and she shook her head at him. "You big softy," she said, obvious affection ringing in her tone.

The Doctor chuckled despite himself. "No need to act so surprised. I do have two hearts," he teased.

"And it makes you a big softie," Donna agreed. She socked him lightly in the shoulder and then gestured at the message again. "Should we drop in on them, then?"

"Do you want to?"

Donna nodded, one eyebrow raised at him, giving him the look she always reserved for the moment she thought he was being too ridiculous for her to deal with him.

"Alright, alright," he said, running his hands down the console. "What do you think?" he asked the TARDIS, smiling when he could feel the thrum underneath his hands that always meant she was responding to him.

"Wait a minute," Donna said, holding up both hands. "Let me find something different to wear. Where are we going, anyway?"

The Doctor glanced over the readout and shook his head, smirking. Of course that's where he'd go as soon as he gets the run of the universe. "Looks like a leisure planet," he said.

"So dress for a vacation. Got it," Donna said, already disappearing down the hallway, leaving the Doctor alone in the console room again.

He leaned back and ran his hand down his face and heard the TARDIS ding in response to how bone-deep exhausted he felt. He patted her gently. "I know," he said. "But if I didn't get attached, if I didn't love them, what would be the point of all this, huh?"

The TARDIS hummed back at him, and he chuckled. "Oh, don't act like you aren't just as invested. You're the one who started keeping those thank-you notes, aren't you?"

The TARDIS dinged, and he laughed again. "Oh, sure. You were keeping them for my benefit." He patted the console. "Love you too, old girl."

The console room filled itself with a warmth that Donna wouldn't have been able to feel with her human senses, a telepathic warmth that felt more like a hug than anything else, though it wasn't quite that, either. But it was meant for him, and it came from the TARDIS, and that was what mattered. The name for the sensation didn't mean anything.

When Donna came back, looking like she was ready for a day at the beach, the Doctor grinned her way and waved her over. "You look lovely," he promised.

She shook her head at him good-naturedly. "Don't I always?"

He chuckled. "Oh, obviously," he agreed as the TARDIS came to a shuddering stop. He patted the console and then headed for the door—and then immediately sighed when he saw where they were.

"What's wrong?" Donna asked. "That's not a good look. Are they in trouble again, or…?"

The Doctor shook his head quickly. "No, it's nothing like that," he promised. He sighed, dragged his hand down his face, and explained, "This is the wrong leisure planet."

Donna let out an exasperated sound from the back of her throat and hit him with the back of her hand. "I thought you knew how to fly this thing!"

"I do!" he defended himself quickly.

Donna gestured out of the TARDIS, both eyebrows raised. "Doesn't look like it, Spaceman."

The Doctor shrugged, shoving both of his hands into his long coat. "If you don't want to stay here…"

"I didn't say that," Donna said, and the Doctor chuckled at her. "You said we can still vacation here, right?"

"Like I can stop you," he laughed, opening the doors to the TARDIS with a flourish.

Donna peeked out and grinned at the shimmering glass that filtered the bright sunlight, at the pools she could already see past the concierge desk, at the advertisements for a waterfall that tourists could come see… She tipped her head at one of the advertising posters. "Midnight, huh? Ever been before?"

The Doctor shook his head, grinning steadily wider at the thought of something new. "Nope. Should be fun."