Author's Note: Okay, what Seo does at the end of this section is really, really smart.


Maria raced towards Clyde, breathless. Her shoes squeaking across the pavement in front of their school.

"He's not here!" Maria shouted. She gestured around them. "I've looked everywhere!"

"Me too," said Clyde, glancing back the way he came. He looked just as panicked as Maria felt — that terrible, wrenching panic tearing at them from the inside. "And no answer from his mobile."

Luke's last class had had a giant walk-out session, early on. The students had all been rounded up, eventually. Before the end of school. But two students had been missing, after the rest were rounded up. Two students who'd left school early.

And guess which two?

"You don't think he's…?" Clyde asked.

Maria whipped out her mobile to call Sarah Jane. Yes. Yes, she did. Luke was possessed. Following Seo. And if they didn't get that alien parasite out of Luke's head, it was going to make him kill Seo. Then himself.

Just like Jason and Vicky.

"You!" shouted an unfamiliar voice.

Clyde and Maria looked up, to discover the girl who'd been talking to Seo at lunch — the tall one, with brown ponytailed hair and a dark complexion — rushing towards them. She now looked frantic, panicked — just as panicked as the two of them obviously were.

She was wearing a school uniform they didn't recognize. Which meant, at a guess, that whatever school she was supposed to be attending, she'd skipped out on her classes to come here.

"Where is she?" the girl demanded. "Where is Seo?"

"We don't know!" said Clyde. "Why do you think we'd know where she was?"

"I… just…" the girl stopped. Frowned, in confusion. Then her eyes went wide, and her jaw dropped. "Oh, no. This… this has to be what she meant. By that whole… spread of influence thing. It's psychically manipulating us. It wanted me to be here. With you two."

On the other end of Maria's mobile, Sarah Jane picked up. There was a hint of sheer terror in her voice, just the same hint all the rest of them had.

"Maria?" said Sarah Jane.

"Sarah Jane, something's happened, we think Luke's—" Maria began.

"I know," Sarah Jane cut in. "Come here fast as you can. I need you to…" She trailed off, as someone else's muffled voice was heard in the background. Sarah Jane cleared her throat, then spoke, again. "Is Alison with you?"

"Who's Alison?" asked Maria.

"That's me — I'm here!" said the mysterious girl, loud enough that the mobile's speaker could pick her up.

"Then all of you come here quick as you can," said Sarah Jane. "I think Luke's going to need it."


The moment they arrived at Sarah Jane's, Sarah Jane began explaining to them what had happened. What had happened with Mr. Smith, how Buffy had shown up — knowing, without being sure how — that Seo was in trouble. Exactly what Buffy had explained about herself and her daughter, and the truth behind Mr. Smith's being hacked.

By the time they reached the attic, Clyde and Maria were on information overload.

They found a short blond woman pacing the attic, restlessly, mobile pressed to her ear, blue eyes fixed on the floor. She seemed desperately worried.

"Apparently, Seo isn't traceable," Sarah Jane was explaining to them. "So we're trying to find Luke. They were the only two that the Headmaster said were missing, after their class was rounded up. We figure, wherever they are, they'll be together."

Maria stared at Buffy. Still not sure she'd caught everything Sarah Jane had been telling them. Buffy actually was… Seo's mum? "But she's too young," said Maria. "If Seo's our age, she'd have to have had Seo when she was pre-pubescent! How…?"

"Seo's father is a time traveler," said Alison. "And Seo isn't your age. She's ninety-nine years old."

Woah. Okay. Right. Alien.

Forgot about that.

Clyde turned to Sarah Jane. "Hang on. You said that you knew a time traveler when you were—"

"Yes, I did, and — yes, apparently, he's Seo's father," Sarah Jane admitted. She looked a little flustered. "But she was genetically engineered, so that says nothing whatsoever about his affections!"

Maria, Clyde, and Alison all exchanged looks. Then looked back at Sarah Jane.

"Never mind," muttered Sarah Jane, turning away. "Let's just find Luke."

Clyde glanced over at Mr. Smith, who looked like he was furiously trying to compute something. He pointed at the computer. "What's he doing?"

"Tracking massive alien energy readings," said Sarah Jane. "Anything that could help us locate Luke. But Mr. Smith seems to be malfunctioning. For no apparent reason."

"No apparent reason?" Alison scoffed. "I can name one. This alien influence thing."

Sarah Jane nodded.

Alison sucked in a breath. "Which means… something's happening," she guessed. "Right now. Something's happening between Seo and Luke, and this alien whatsit doesn't want us interfering until it's too late to stop them."

"My thoughts exactly," said Sarah Jane.


Luke found Seo in the warehouse. The warehouse where she'd built all her machinery. The machinery she'd use to end the world, blast it into small fragments of rock, floating through space.

Evil. Murderer. Killer.

Luke went inside the warehouse. Studied the equipment.

He knew what was going on, now. Knew it with every fiber of his being. That she was a creature of pure evil. Trying to destroy humanity. Trying to kill his mum. Trying to manipulate the universe to her own ends.

And here she was, like a gift to him. Lying here, on the floor — bound, helpless, and unconscious. Unable to stop him from modifying the machinery to his own advantage. Unable to run. Unable to get away. Unable to even look at him with those bewitching eyes.

Killer. Murderer. Seosyrae must die. Seosyrae will die.

She tried to destroy the world.

Die forever. Die to give us life. Die to restore godhood.

Now Luke would destroy her.

He got to work.


"I don't understand," said Clyde. "What's going on?"

But before he could get an answer, Buffy gave a breath of relief, muttered a hurried, "Thank you, Tosh," then snapped her phone shut. She turned to Sarah Jane. "Got an address."

"Close?" asked Sarah Jane.

"Guess again," said Buffy. She turned to Alison, gave her the information as fast as she could, then turned back to Sarah Jane. "We've got to get over there. We might already be too late."

"Wait, what…?" asked Maria.

Buffy swung around to face Maria. "There's something in your friend Luke's head," she explained. "Something alien. Something with vast enough psychic powers that it's been manipulating all of us. It's trying to drain Seo's lives and absorb them in order to do something seriously evil, and unless you can figure out what this alien thing is and how to get rid of it, both Luke and Seo are going to die, and the world is going to end."

"That's your job," Sarah Jane agreed. "To stay here and figure out what this is, and how to defeat it."

Maria, Alison, and Clyde looked at one another. Realizing, for the first time, the pressure they were under.

"And where are you going?" asked Maria.

"To find Luke!" Sarah Jane called back, as she and Buffy left the attic.


The car, of course, conked out half way there.

"I didn't think they could influence something like a car," Buffy muttered, getting out of the passenger side, and beginning to run towards the warehouse Tosh had told her about. "I thought it was just psychic. But then Seo doesn't usually tell me anything, anyways."

"Do you think we're too late?" Sarah Jane asked, rushing to catch up.

"Cardiff should be far enough away to escape this alien's spread of influence," Buffy said. She gritted her teeth. "It just… has to be. Because if not, then Seo's… already…"

She choked on the words. Couldn't get them out.

"If she's as clever as her father," said Sarah Jane, "she'll find a way out of this. I'm sure."

Buffy glanced back at Sarah Jane. Remembering what Sarah Jane had said about her own son. Remembering just how clever he was. They were using a genius mind — because it was the only mind smart enough to know how to destroy someone like Seo.

"Unless your son's brain is cleverer," said Buffy, racing on ahead.


Seo woke up.

She could feel herself hanging, suspended, in midair, her body bound with ropes and clamped tightly between two big metallic things. She tried to wriggle, tried to break free, but her limbs felt like jelly. And she could smell the energy buildup searing around her.

"I knew it was a trap," she muttered.

And she'd walked into it anyways. Because she couldn't let the Earth get destroyed. Just couldn't.

Her eyes began to focus, and she peered out at her surroundings. Making out shapes in the blurs. One moving — human-looking. Not Slitheen, then. That was something, at least.

But as the blob came into sharper focus, Seo felt her hearts sink. Because she recognized who it was manipulating the machinery.

"It was you," she muttered. "All along." She gave a long, slow sigh. "I really hoped it wasn't."

Luke didn't answer, his bloodshot eyes focused on his work, his entire expression bent in anger, rage, and determination.

"I liked you, you know," said Seo. Her mind racing through ideas for how to get out of this. "And I thought… maybe… you liked me, too."

"You killed your dad," said Luke, his voice thick with angry resentment. "He raised you. And you murdered him."

Definitely the entity, then. Not Luke at all. He'd never have known about that.

If only Seo had had better psychic shields when she'd first run into Vicky!

"Luke," Seo called. She tried to roll a little, just to lever herself out of the center of the energy buildup, but didn't have the strength. "Listen to me. This isn't you. You never even knew Dad."

"A murderer," spat Luke, turning on her, advancing towards her. "A killer. A thing to be wiped out. A blemish on creation itself!"

Good. Brilliant. Keep him talking. Keep him focused on her, and not on the machines he was fiddling around with.

"What about you, Luke?" Seo asked. "How are you any better, killing me? When's the violence going to end?"

Luke stopped, in the center of the warehouse.

"Talk to me," Seo urged. "Tell me about things you like. Things you know. Tell me about… wiring diagrams! You like wiring diagrams. What would a transistor look like?"

Luke hesitated. Then gave a cruel, cold laugh. "Oh, no," he said. Turning back to the machines. "You can't distract me that easily." He reset some controls. "I'm too clever to keep talking while you think up some way to escape. Don't try to curb my power with your words."

"Luke, listen to me!" Seo shouted. Struggling to gain some purchase. How could she possibly feel this weak? "This isn't you! I know this isn't you! You don't want to kill me!"

"Yes, I do," said Luke. "I want to crush you, Seo. I want to burn you to nothing. I want to watch you die, and know you'll never come back."

His eyes grew redder and redder with every word he spoke.

"Tell me about your mum," Seo pleaded. "About your friends. Tell me about yourself, Luke. Your hobbies. Your interests. What do you like to do, in your spare time?"

"I…" Luke stopped. Hesitated. "I… don't…"

"Who created you?" asked Seo. "What group of aliens? For what purpose? Were you created from someone, or were you created as a generic human template? How'd you meet your mum? What's your story?"

Luke opened his mouth, but no words came out.

"I'm like you, Luke," said Seo. "I was created. Built by a group of scared humans who didn't know what they were doing. Imprisoned in isolation for 98 years, then shoved into the larger world without any preparation. I know how you feel."

"You don't—"

"It's lonely," said Seo. "Terrifying. It feels like everything you do is wrong. Everything you know needs to be hidden. You try to fit in, try to be normal, but you can't. You're always going to be different." She gritted her teeth. "And that hurts."

"No!" Luke shouted. He glared at her. "You can't trick me. I… I know you have to die! I know—"

"But you don't," Seo said, trying to keep her voice level. Calm. "You know this isn't right. You know — whatever they've convinced you is real — doesn't make sense. You're clever enough to see through it."

Luke clutched at his head, teeth gritted.

"You're too clever for them," Seo urged. "You can't…"

Luke lunged at the controls, shoving a big lever down.

Seo felt a zap sear across the metal plates holding her in place, surging through her body. She could feel something powerful draining her, slowly but surely, bit by bit, squeezing the life out of her. It would continue, on and on, she knew, as she died and came back, died again and came back again, until she had nothing left to give.

She clutched at her life energy as tight as she could. Unwilling to part with it.

"Luke!" she screamed. "Stop!"

The energy fizzled out, as Luke slammed the lever off, a sudden look of utter horror crashing across his face. He stared at Seo, his mouth open, trying to figure out what he'd done and why he'd done it.

Seo tried to move, but was even weaker than before. "Machine…" she breathed. "Must produce… psychic… paralyzing agent. Interferes… with…"

But it didn't interfere for long. No sooner had Luke begun to rush over to release her, he stopped. The anger and resentment came over him, again. His eyes turned red, his hands bunching into fists.

"You will die," he told her. "Blood for blood. You must die."

"Luke…" Seo tried.

"No!" shouted Luke. The alien entity clearly struggling to regain its previous control over his mind. "You have to die! I have to be the one who kills you! Those you killed are never coming back! You shouldn't come back, either!"

Then he spun around, and reached for the lever, again. Seo closed her eyes, knowing this was a bad idea, but knowing it was her last, desperate hope. And began to tap a rhythm against the metal behind her.

A series of four beats. Repeated over and over again.

Tap-tap-tap-tap. Tap-tap-tap-tap.

"Luke," said Seo. Her voice so weak, it was barely above a whisper, now. "Please. Look at me. Look at what you're doing. Do you want to do this?"

The redness faded from Luke's eyes. He stared at Seo, confusion flooding his features.

Confusion that settled into utter panic.

"I… I'm trying to…" Luke looked down at the controls, then jumped away from them, as he realized what they were. What they'd do. "What am I…?"

"You're under a psychic influence," Seo said. Trying to keep the rhythm up. "Right now, I'm blocking it… using… another psychic influence." One she didn't completely understand. One that she only knew was evil — very evil — but didn't want to kill her, specifically.

Or, at least, she didn't think it did.

But every tap of her fingers against the metal was eating up her last few ounces of energy. Every movement felt like she was trying to lift a whole planet on her shoulders.

"There's something in my mind," said Luke. He grabbed at his head. "Something in the air. I should have felt it, earlier. It's… evil. Alien. Manipulating us. Driving us all to this point. It wants… it wants me to… kill you… so it can grow. It wants me to…"

He stumbled away from the device.

"Please, Luke," said Seo. "Let me go. Let… me…"

But she couldn't keep it up any longer.

She'd expelled too much energy, already. The world was quickly fading around her, and she found herself plunged into the icy darkness of unconsciousness.