Author's Note: I can totally see the Doctor saying that, when he was Seo's age.
Martha decided she should probably take Seo away for a little while. Leave Buffy and the Doctor to talk a little, in private. Since, it was pretty obvious, they had rather a lot to talk about.
"You like him," Seo said.
Martha wasn't really sure how to react to this. Yes, she liked the Doctor. In a way he definitely wasn't reciprocating. And, yes, when Martha had first seen Seo, there'd been a certain amount of disappointment involved. But since Seo wasn't real… and none of that really happened, in the Doctor's future…
Which led into a whole other lot of awkward topics.
"I…" Seo started, then looked down at the ground, a blush on her cheeks. "I… like someone. Like that. Back on Earth. And he…" She bit her lower lip, her cheeks turning redder. "I don't know if he likes me, back."
Martha glanced back at Seo. That… hadn't been where she'd assumed this particular conversation was headed.
"You fancy someone?" asked Martha. Her curiosity was getting the better of her. "Who?"
"He's just… this… human I know," said Seo. She twisted her foot into the ground. "But he's brave. And heroic. And kind. And… I just... like him. A lot." She looked up at Martha. "What do I do about something like that?"
Martha wasn't exactly sure why Seo was talking to her like she was the romance expert. But apparently, the Doctor's kids were just as clueless about romance as he was.
"Have you tried asking him out on a date?" Martha offered.
Seo opened her mouth to reply, when a loud snarl from their right cut her off. They both turned, to find a huge shadowy figure, towering over them, its eyes blood red and its talons raised. Beside it were a group of black-robed figures with sewn-up patches for eyes.
Martha and Seo looked at one another. Then turned, and tried to run.
The shadowy monster swiped its claws down, snagging one of them on Martha's jean pocket and jerking her through the air. She shouted for help, flailing, trying to break free. Her eyes darting around to look for some way out of this.
There!
A torch, lying against the wall. She grabbed it up, as the monster flung her around again, and swung it so the fire burned his hand.
With a roar, the creature dropped her on the ground.
She hit the stones with a thud that shook through her whole body. Martha cringed, as she got to her hands and knees, making a mental medical checklist. Everything seemed okay. Sore, yes, but okay.
A shout, and a cry. Martha looked up, to find Seo surrounded on all sides by various nasty creatures, shouting at Martha to run — get help, tell the Doctor and Buffy!
Then one of the eye-patch, dark robed creatures raised up its arm, wielding a knife, and thrust it towards Seo.
She caught the creature's arm, flipped it over her head and then ducked the blow from the one beside it. "Go!" she shouted to Martha.
The monster that had picked Martha up, before, reached out for her, again, trying to block her way. Martha grabbed up the dropped torch, as she struggled to her feet, lunging at the monster to scare him off, get him away for long enough that she could find the Doctor.
Turned out, she didn't need to.
The shouts and growls and hisses must have alerted them, because Buffy and the Doctor came rushing down the hall to find out what the trouble was. The Doctor rushed for Martha, double checking that she was all right, while Buffy began to kick, punch, and flip her way through the monsters towards Seo.
In the center, Seo had begun, out of desperation, using the super-strength that Martha had heard she hated using. Throwing the monsters away from her with such violence that they cracked the stone walls nearby. But she was still being overwhelmed, swarmed from all sides.
The Doctor raised up his sonic. Fiddled with the settings, muttering about synchronizing with the machine. Then, looking at Seo and the creatures with determination on his face, he pressed the button, and the sonic screwdriver buzzed into life.
None of the creatures seemed to notice.
"It's not working!" Martha shouted at the Doctor.
"Isn't it?" the Doctor asked her.
Just then, appearing mid-leap in the air, dozens of giant, hairy brown beasts with snouts and a single horn on their heads shimmered into existence around them, materializing into both this location and this dimension with a suddenness that took both Martha and the beasts themselves by shock.
But not for long.
"Get 'em, Aggedors!" the Doctor shouted, changing the sonic frequency.
The Aggedors turned, noticing the evil creatures, and, as if driven on by the Doctor's signal, launched themselves at the monsters surrounding Seo with feral roars. The Aggedors clawed, ravaged, and tore at the creatures as they overtook them, horns slamming the evil monsters out of the way.
The evil creatures, distracted, turned their attention away from Seo, who managed to punch a green-skinned vampire in the stomach so he reeled. She then slid and leapt out of the way, trying to reach Buffy, who'd made it about half way to her.
Buffy gave a spinning kick that knocked three creatures out of her way, then lunged for Seo.
Only she never made it.
One of the cloaked figures thrust a dagger deep into Buffy's chest, as she passed by. Then sharply out, the blood seeping forward, covering her shirt. Buffy stumbled, her left arm caught by the giant shadowy monster, who swiped down with his claws, and sliced through her.
Buffy fell, dead, to the ground.
Seo screamed.
And inside of that scream was a rush of something icy. Something cold. Something that flashed through the entire stone fortress — and maybe even beyond — with a powerful destructiveness that burned across all of Martha's senses. Martha clutched her head, as her vision faded into a silvery white, trying to keep herself together, trying…
A lurch, deep down inside. Like someone had just yanked her inside out and back again.
And then it was gone. Like it had never been there at all. Martha looked over at the Doctor, who also seemed fine. Physically. His face, however, had gone very grave, his eyes examining the scene in front of him with an anger he didn't seem to know quite where to direct.
Martha looked over… to find…
Buffy. Sitting up on the floor, where she'd fallen, looking a little dazed but otherwise completely fine. Not even her shirt was bloody or torn.
And surrounding Buffy was a sea of bones, ash, and dust. A few decomposing corpses, here and there, but most of the creatures' remains were skeletal.
Martha could see the remains of the Aggedors that had rescued them, mixed in with the remains from the others. All wiped out together, in a tidal wave of fury and desperation.
Martha rushed over to check over Buffy. Make sure she was all right, medically. But she appeared undamaged. Unharmed.
"This is starting to become a habit," Buffy muttered, almost too faint for Martha to pick up.
The Doctor stepped forward into the sea of destroyed creatures. Kneeling down, analyzing the bones more closely. "Aged to death in a matter of seconds," he diagnosed. "Which is particularly impressive… because, for some of these creatures, age wouldn't be enough to kill them." He picked up some of the dust, sniffed at it. Wrinkled his nose. "Consequences of a sudden, accelerated, destabilized time field — at a guess."
He looked up, towards Seo, who was standing with her back plastered against a stone wall, her eyes staring out at the devastation around her.
"You didn't know you were going to do that," the Doctor guessed. He stood up, putting his hands in his pockets, strolling towards Seo. "Did you?"
Seo looked up at the Doctor, a terrified expression on her face. "What did I do?"
The Doctor stopped, just in front of Seo. "You mean you don't know?"
Seo shook her head.
"So it's feeding off your subconscious," the Doctor muttered. "Whatever it is." He noticed Seo's still terrified expression, and decided a hurried explanation was in order. "You didn't want your mother to die. So you forced time to turn backwards — at least in relation to the four of us." He gestured at himself, Martha, Buffy, and Seo. "You created a stability field around us, only de-aging us about a minute, but didn't shield anyone else. And, well, every action must have a reaction."
"So we got younger," said Martha, "and everyone else got older?"
"Yes; in this case, drastically so," the Doctor agreed. "Without the proper shielding or a stabilized time interface, the aging effect never stopped. They went right on until they were dust. Either from age, or — in the case of the vampires — an overload of temporal friction." The Doctor ran a hand through his hair. Then turned back to Seo. "But all of that is secondary. Most important is — how could you do something like that without knowing?"
"I… don't know," said Seo.
The Doctor leaned down, so he was at Seo's height. Put on his very best, 'Trust me, I'm the Doctor' look, and held out his hands by her temples. In a soft voice, he asked, "May I?"
Seo shrunk back. "Don't," she whispered.
The Doctor frowned, took away his hands, a thoughtful expression on his face. "You didn't know you were going to say that, either," he noted.
Seo didn't answer. She looked incredibly uncomfortable.
"Whatever it is," said the Doctor, "it's feeding off your subconscious. And I think your subconscious doesn't want to let it out."
"I don't understand," said Seo.
Buffy stepped forward. "Doctor," she said. "What's wrong with Seo?"
The Doctor sighed, then turned to face Buffy. "Well, I don't know. Yet. But I'm beginning to have a few suspicions. Rather nasty suspicions. And I think," turning back to the room with the machine, coattails flying as he rushed back there, "we should test them out!"
The others raced after him.
"What kind of suspicions?" Buffy shouted. "Why—?"
The Doctor stopped. So did the others, as they noticed the bodies lying in front of them, blocking their way back to the room where they'd left Seo's machine.
Martha's jaw fell open. "But… but those are people!" she cried. Raced forward, tried to find a pulse, or some indication that they could be saved. The bodies crumbled into dust beneath her touch.
"Peladonians," the Doctor agreed. His eyes shifted across the bodies, resting on one in the far corner of the hall. "Most of them."
Buffy furrowed her brow. "How'd they get here?" she asked. "We went all around this castle, and there was no one. I thought nothing living could get into this dimension." She hesitated, remembering the Aggedors. "You know. Without using that machine thing."
The Doctor raised an eyebrow at Buffy. "You came here. Didn't use a machine."
Buffy's eyes rested on the dead bodies, and she stepped back. As she seemed to understand. Glancing over at Seo, whose face had turned white. "Seo…?"
"The Peladonians were forced into this dimension too quickly," the Doctor explained. "Sensory overload must have knocked them out. They'd have been unable to even cry out when the time distortion hit them." He ran a hand through his hair, letting a breath out through his teeth. "Which means whatever this 'silver stuff' really is… it can transcend any dimensional barrier at will. Easily."
Buffy swore beneath her breath.
"Exactly," the Doctor agreed.
Martha called out to them, as she reached a body unlike the others. One that seemed to ripple, fading in and out in the air. Whose skin was almost insubstantial, felt like nothing beneath her fingers, yet impacted and dented beneath Martha's touch.
The others rushed over, and Buffy recognized the face. So did Seo.
"Andor," Seo breathed.
Martha frowned. Recognizing the name from what Buffy had told her. She looked up at the Doctor. "One of the Powers that Be? I thought they couldn't die. Even from… 'temporal friction' or whatever you just said."
"They shouldn't," the Doctor confirmed. He glanced over at Buffy, who was smiling faintly to herself. "You don't seem too upset."
Buffy looked back at him, realized her mistake, and tried to hide her smile. "Oh," she said. "Yeah. Yeah, that sucks. Seo's super destructive and can't control it, and… and…" The smile peaked out, a little, as her eyes rested on Andor. And she remembered what Andor had done, the pain he'd caused her and the Doctor, in 2004. The lengths he'd gone to, so he could prove that the Powers that Be should kill Buffy's daughter.
"Can we kill him again?" asked Buffy.
The Doctor gave Buffy a very severe look, which she met with her own. For a few seconds, they stayed that way, neither wanting to back down.
"Doctor," Martha cut in, before this could go on too long. She stood up, and walked next to Seo, giving her a friendly and supportive smile before addressing the Doctor again. "What's happening to Seo?"
The Doctor turned to Martha, and gave her a perky grin. "Nothing," he assured her. "Well, I say nothing. Something. But not something you need to worry about. Not for long, anyways. After all! Seo is going to be fine. She didn't go through a full regeneration cycle, and that means she's not getting the full dose of this. Seo's still mostly in control."
"Whatever what thing is?" Buffy asked, warily.
The Doctor's confidence faltered. "I don't know. Yet. But I'm going to find out."
He turned, and ran back into the room with the machine, yanking two wires out, and then flipping a switch on the top. The machine hummed into life, again.
"Okay, just answer one question," Buffy said, entering the room behind him, Seo and Martha in tow. "Is Seo really as dangerous as the Powers that Be think she is?"
The Doctor glanced over his shoulders. "Seo is being infected by an energy that can kill anyone — regardless of who that person is and how immortal they might be — across all of time, all of space, and any dimensional barrier. An energy that activates with only a thought from Seo. She could probably tear apart entire civilizations — topple empires, destroy planets, wipe out entire species — with only a nod from her subconscious. And, worst thing is — she can't control the energy. At all." His eyes rested on Seo. "I'm sorry. I am so, so sorry. But the answer is… yes. Yes, you really are that dangerous. If not more so."
Seo said nothing. Just stood very still in the doorway to the machine-room. Trying to look brave, but utterly failing.
"But you can fix her, right?" Buffy reminded the Doctor.
The wall nearest to them burst with brightness, as it opened into a tunnel of softly glowing white light, inside of which was a staircase that stretched on farther than anyone could see.
"Working on it," the Doctor told her.
Martha pointed at the staircase. "Where does that lead?" she asked.
"The Axis," the Doctor said. He clapped Seo on the back. "Cheer up. You're going home!"
"My home," Seo said, her voice little more than a whisper. "My prison."
"Blimey, you sound like me, when I was your age," the Doctor muttered. He grinned, then charged forward. "Still! Only a quick trip! Allons-y!"