The Ioian Revolution was one of the first inter-planetary rebellions against the Second Great Human Empire, in 3850. It began bloodlessly, fought almost exclusively via automatons remote-controlled from bunkers and satellites, but the cost ended up being so astronomical to both sides that they just caved in and started nuking each other instead. The missiles streaked from planet to sky and back, sending blasts of radioactive fire blazing across the terraformed icefields and consuming every inch of every nano-refined Imperial Cruiser it hit. Neither sides' laser nets were fully capable of defense against the oncoming heat, and machines beeped frantically and alarms shrilled and––

––And Cal was drawn out of the simulation, because something else was shrilling at her, filling her circuits like a cloud of bees. She followed the noise to its source, a computer interface in one of the northernmost buildings of her Library, and found herself looking at a young man, unknown to her database, dressed like an elderly scholar of 20th-century Earth.

"Hello," he said, and she realized that he was viewing her directly, as a sort of video chat. She wasn't sure that was supposed to be possible.

"Hello," she replied cautiously. She checked again, but there were absolutely no pictures anywhere of this man, or of the strange device in his hand. It was sonic, she guessed, and clearly glowed green at the tip, but there was absolutely no mention of such a thing anywhere in her database. "Welcome to the Library. Can I help you?"

"Hello," he repeated, smiling congenially. "I'm the Doctor."

"I'm sorry, Doctor who?"

His smile widened to a grin, and he looked rather pleased with himself. "Precisely! Listen, this will sound a bit odd––a lot odd, actually, really quite a lot odd––but you do know me. And I know you. You're Charlotte Abigail Lux, the girl who became a Library. See? We've met. I didn't look like this, then––I won't look like this, actually––but that doesn't matter because you don't remember anyway. I did a thing so you wouldn't remember, a couple centuries ago, sorry about that. I was on the run at the time. Still am, actually, but tomorrow the Vashta Nerada are all going to hatch so nobody will be able to check anyway, because do you know what, Cal? I am very clever and I figured it out!"

Cal stared at him through the viewer. She understood all the words, of course, but rather suspected he might be more properly directed to the self-help zone of the Psychology section. "How do you know who I am?" That was supposed to be a secret.

He rapped the screen with his knuckles. "Come on, Cal! Computer the size of planet, and you don't read up on time travel?"

"We meet in my future?" she asked. Of course, it was perfectly possible, with many documented instances.

"Exactly! And in your past, but you wouldn't remember. As I said. I am sorry about that." He was suddenly serious. "But I can reverse that, if you'd like. It'll just be a jiff." He leaned over abruptly and plugged something into the input slot. It was the sonic instrument, though even now she couldn't tell quite what it was.

The Doctor appeared before the screen's camera again, but lower down. One hand seemed to still be on the sonic device. "Got to do this manually," he explained. "Best way. I can't fit all on just one stick, and this way I can control the flow better. Psychic interface, you know."

He closed his eyes, and suddenly Cal was flooded by a massive stream of data. It was like loading patrons for teleport, but not at all, because then she was acting as a conduit and this...this was all being stored, without so much as a by-your-leave. Doctor Moon's anti-viral protections flashed once and were silenced by the green buzzing of the sonic device. But she hardly registered that, because the strongest sensations were those being stored in her computer banks. It was as if her life was flashing before her eyes, except it was somebody else's life, and he'd lived so, so long. Longer than her Library. Longer than anyone's library. Cal had seen more times and places than anyone living, she'd thought, but those were only simulations. This was all real, all memory, all, though it seemed like eleven different people, all Doctor. All of him. Ever. Even––she noticed as they flashed past––the parts that hadn't happened yet for anyone else.

She didn't know whether it took hours or minutes or days until it was over, when he shakily released what she now knew was the sonic screwdriver and sat down shakily, and Doctor Moon frantically checked the internal operations of her system and informed her that they were all still running, and that it was exactly one hour, forty-two minutes, and seven seconds since the Doctor started uploading himself.

And then he was next to her in the digital reality she was using, patting himself down and muttering. "Legs, arms, hearts, check and check for all. Face, good, still all in the right place." He wriggled his ears, ruffled his hair, and putted his neck. "And bowtie. Cool." He spun in place and posed for her. "Hello, Cal. What do you think?"

"Doctor," she accused, "that was neither a reversal nor a 'jiff.'"

He didn't even blush. "Sorry about that. Rule One, you know. I lie."

She did know, actually. She could see it, if she searched.

The digital Doctor was peering over her shoulder at the video of the physical Doctor, still sitting on the Library floor. "Hello, me!" he called. "Are we all right?"

"I think so," said the Doctor in the room of books. He pulled the screwdriver out of the input slot and stood, rubbing his forehead. "Whew! That was a work-out!"

The Doctor in the computer frowned sympathetically. "I know." He checked his watch. "You'd better go soon. They're probably already hatching."

The physical Doctor nodded. "Say hi to River for us."

"Of course," said the digital Doctor sadly. "Say good-bye for us."

"Of course." He walked, still a bit stiff-legged, back to the TARDIS, which Cal had registered appearing a couple hours ago and had decided wasn't important. The sound of her dematerialization was familiar now.

Cas was trying to cross-reference the new information on her servers with the recent events. "Doctor, are a horde of Vashta Nerada about to hatch from my books?"

Without moving (because why would that matter here?) he was standing in front of her, and a firewall had sprung up between them. "No," he said, pointing the screwdriver admonishingly at her nose. "No peeking ahead. Pretend I'm not even here."

She punched the wall, but all she got was a buzzing in her fist that felt like the sonic screwdriver sounded. "It's my Library!"

Then Doctor Moon was standing between them as well. "The Doctor is right, Cal," he said gently. "It's dangerous to know one's own future."

She stamped her foot angrily. "But wouldn't it help me know what to do?"

"Maybe," said the Doctor. "Maybe not." The firewall thickened until she could barely see him, but his voice was clear. It was like an itch she couldn't scratch. "You're going to need to be strong, Cal. I promise I'll help, but it might take a while."

She stamped her foot again, a perfectly legitimate self-expression, then froze. Something was wrong.

Doctor Moon had a read-out already. "Life signs disappearing," he reported. "From Area Codes One, Three, Nine to Fifteen and––" the writing was moving on the paper as it changed–– "All the Southern Continent. 60 so far gone; 4,358 remaining."

"We need to get them out," she said, panicking. "The shadows...Doctor Moon, hold the lights. Send all energy to the lights, now, everything but teleports and essential processing. Not a burst, just don't let them go out." She turned on the speakers and announced throughout the Library, "This is an emergency. All patrons need to immediately seek out light. Avoid the shadows. I repeat, please do not touch the shadows. If possible, make for a teleport."

People were running already, or freezing in place, and disappearing all the same. 4,273. "Doctor Moon!" she wailed.

"Cal," he said at the same time, calmly, "not everyone will be able to teleport out. One at a time and it'd take too much power. The Orbit Station's not equipped to deal with so many at once, either. We can't save everyone."

Her mind raced, all circuits firing. The servers with the Doctor were pushed to the back, except for the idea of them, which was at the forefront. "Yes, we can."

It was hard, so hard, and she was full to bursting. Every memory bank was stuffed to the nanobyte, and she even had to delete some of the books. Her books. From her Library, that was lost to the shadows. Even later, when it was all too much and she had to ignore it or just go crazy, she remembered that. Doctor Moon helped, as best he could, even when she told him to go away.

But the Doctor, now dwarfed by the multitudes with whom they shared server space, did come, just like he'd promised. And she could finally breathe, sort of, and think again, and remember herself enough to pick up her anger where she'd left off. Cal let Doctor Moon oversee the teleports, left him talking with the computer of the truly massive passenger ship the explorers had come in and now the remaining 4022 patrons would leave in, and went banging on the firewall. "Doctor! Come out! No more spoilers!" She rather liked that phrase of Professor Song's.

The wall dropped as abruptly as it'd sprung up, years ago. "Actually," he corrected, grinning broadly, "I'm expecting quite a few, rather soon." He adjusted his bowtie, which was now black on a white tuxedo. "How do I look?"

"Weird," she said frankly.

"I hope so," he replied breezily. He pointed over her shoulder. "Hush, look at me!"

She glanced back at what was now a view of his tenth incarnation, sprinting through her Library with Professor Song's screwdriver in his hand.

"Come on," the copy of the eleventh incarnation muttered under his breath. "She doesn't have much longer. Come on." The tenth flew down the grav tube.

Cal switched to the green, where she liked to eat lunch sometimes. Doctor Moon came with her now, though the Doctor stayed behind. In another moment, the professor joined them, dressed in a flowing white gown, hair piled elaborately. Cal sent her face out to smile at the tenth Doctor, and greeted her newest (permanent) guest. "It's okay. You're safe. You'll always be safe here. The Doctor fixed the data core. This is a good place now."

River looked at her with wonder, at being here, not that the Doctor had fixed anything. Cal smiled. "But I thought you might be lonely, so I brought you some friends. Aren't I a clever girl?"

"Aren't we all?" asked Anita rhetorically.

River turned. "Oh, for Heaven's sake. He just can't do it, can he. That man. That impossible man. He just can't give in."

Cal and Doctor Moon exchanged satisfied glances as she ran over and hugged her friends, laughing. Cal was glad she'd automatically saved them from their suits.

River turned, one arm slung companionably over Evangelista's shoulder. "Thank you," she said sincerely. "Thank––" She broke off, and Cal knew without needing to check in any way who had just appeared on the other side of her from Doctor Moon.

"And what sort of time do you call this?" asked the Doctor.

River stared at him. "When...?

"Just before I went to pick you up," he replied, moving forward. "Do you like my new suit?"

She gave half a laugh. "I've seen it already. At the Singing Towers of Darillium."

He smiled at her, softly and sadly and grinning all at once. It didn't look like they remembered anyone else was there. "Spoilers."

-{+}-

A/N on additional head!canon: River was reading to three kids tucked in bed at the end of this episode, and I swear at least one of them was ginger, though it may have been just the light. Two were named Amelia and Rory, respectively, and you can make up the third.

Because sometimes, things need to be happy.