Author's Note: Oh, it's getting tense! Who will Seo choose? How will she tell?

Find out!

Enjoy!

Seo set Willow back into her wheelchair, as the elevator rose. Up and up, right to the top. To where that portal was situated. To where her Mom was being held.

Xander had put the gun away, into his pocket.

"But I'm not going in defenseless," Xander insisted, fingering it. "Elizabeth's a nutcase. I'm not letting her get away with it."

"Just make sure you shoot the right one," Willow said, with a sigh.

Xander tapped his sightless eyes. "They say blind people get super senses, to compensate. Maybe I'll know, even when you two don't."

"They also say that blind people shouldn't use guns," said Willow.

"Except in Texas and Michigan!" Xander replied. He flashed Willow a grin. "And considering, after the apocalypse, there's no California or United States anymore… I've decided that counts."

The elevator came to a stop.

"Brace yourselves," Seo warned the others.

As the doors pinged open.

The three leapt out — or, at least, two of them did — ready to face whatever lay inside with every bit of bravery and determination they could face.

Instead… they found two locked up versions… of Buffy.

"No, Seo, it's a trap!" shouted one.

"The Crystallizer!" shouted the other, pointing. "It's blinking! There's stuff going on, Seo! Stuff that's bigger than you and me! Except she—"

"Stop talking like you're me!" shouted the first, irritated. "Geeze. Do you really think she's falling for that? I mean…" Trailed off. Noticing Willow and Xander. "Oh, my God!"

"Oh, God! Willow?" said the second. "Xander? What happened to you?"

Willow rolled her wheelchair out.

Then stopped.

"Oh," said Willow. "I… see."

And Xander faltered, his hand inside his pocket, pulling out his gun. "Uh… little help, here," he said. "Anyone want to tell me which I shoot?"

Seo looked between the two. Faltering.

"Look, you guys, be careful!" said the second Buffy. Pointing at the other one. "She's a nutcase. You've got no idea what she'd be willing to sacrifice to—"

"Shut up!" snapped the first Buffy. "She's my daughter! You're just the nutcase trying to… to… I don't know! Impersonate me!"

"Oh, yeah, that'll convince her for sure, Elizabeth," said the second Buffy, rolling her eyes. "Yell a whole bunch and get really angry. Because that's totally what I do."

"Seo, Willow, Xander," said the first Buffy. "We've got to get out of here. Like, right now. There's no time! That Crystallizer… it's projecting through the link! Into both worlds! Stuff's being manipulated and every second we delay, things'll get worse and worse."

"She's crazy, but she's right," said the second Buffy. "That Crystallizer is bad with a capital B. The longer that link's open, the more chance there is that stuff from the Time War will spill out into our world."

"Your world?!" shouted the first Buffy. "You liar!"

"I'm the liar?!" shouted the second.

Willow's face was stony. As she examined the two, from her wheelchair. The two different identical faces, sporting the same identical bruises, scratches, and injuries.

Seo walked forwards. Hesitantly. "You… both know who I am?"

"I'm a Line Hopper, and so is she," said the second Buffy. Pointed at the first Buffy. "She used the Crystallizer to steal my memories. Including those of you."

"Don't trust her, Seo," said the first Buffy. "She's gonna use my memories against you. To trick you. I'm the real Buffy!"

The second Buffy just gave a small laugh. "Pretty defensive, huh, Elizabeth?" She looked out at Seo, fondly. "I told you. Seo will know. She's smarter than you think."

"No, I told you that!" shouted the first Buffy. "She's my daughter!"

"She's my daughter!" snapped the second.

Xander faltered. "It's… the one on the left," he said, pointing his gun at the first Buffy. "That's Elizabeth. Has to be. The other one's nice, while this one's… just… defensive and shouty."

The first Buffy raised her hands.

"Xander, please," said the first Buffy. "In my world, you're my friend. Whatever she's done to you… you can't end it with violence."

"Like I said to Willow, back when she was all with the goth-girl evil-magic," said the second Buffy, "no one has a license to kill. Humans have laws and rules that deal with this kind of thing. We can't just throw that away for—"

"Laws and rules that Elizabeth destroyed," Xander said, his voice icy. "When she destroyed the world."

Seo raced out, and grabbed Xander back.

Hesitating, as she looked between the two identical versions of her mom.

"Come on, Seo, you know it's me!" said the first Buffy. "Tell him!"

"Yeah, and the more you try to shout at her, the more she knows it's not you," said the second Buffy. With a grin at Seo. "Seo. Never doubted her. Never will."

Seo recognized the words.

Surely… only Mom would remember… except no. No, Elizabeth was using something to read Mom's memories. Elizabeth would know, too.

"I… don't…" Seo began. Then realized… "Slayer strength! Only one of you will have that!"

"Yeah, and these bruises and things are because I walked into a door," the second Buffy said, pointing. "We're Line Hoppers, Seo. Like two sides of a sheet of paper. Elizabeth's tearing through that paper so we'll blend together, and you'll take her home instead of me."

"She brained me with an iron bar," the first Buffy supplied. "Then went on this evil villain rant about how she's more important than the universe."

"Yeah, you did," said the second Buffy. "Total Big Bad stuff."

"I… I don't…" Seo stammered.

Willow cleared her throat. "Let me handle this," she said. Wheeling herself out in front of the two. Pausing, in between them, her eyes darting between the two different copies. Then, in that way she always did, said, "Hello, Elizabeth."

The two both gave the same reaction Willow remembered from all her visits.

And a little start, at the name, as if not exactly used to it.

"This is you all over, huh?" said Willow. "Always pretending to be something you're not. Someone you're not." She paused, reflecting. "How'd you manage to get all the injuries to match up?"

Both Buffies began launching into a dizzying explanation of the Crystallizer. What it did. How it messed with Buffy and her timeline-screwed-uppedness. About the Powers that Be and the sealed-off timelines in the back room of the Axis.

Willow absorbed it, calmly.

Then gave a little laugh. "And suddenly, it all makes sense," Willow said. "You came prepared, huh, Elizabeth? That's your giveaway. Why it's so obvious which of you is—"

A screech.

And a demon leapt out from the ceiling, where it had concealed itself. Dove onto Willow, its jaws open, claws extended…

No one having a second to react, before the demon had severed Willow's head from her shoulders.

"Willow!" both Buffies screamed. Scrabbling at the bars, trying to bend them open, get out and help.

Seo raced over to the lab table, slammed down a button.

A shimmery force wall was thrown up over the front of each of the cells. Knocking both Buffies back against the far wall.

Seo wasn't letting them scramble themselves around. Confusing which one was which, so she couldn't choose even using the few clues she'd been given.

Not now.

Xander had already located the screech of the demon, and blasted it apart with his gun. Then raced over to Willow, his face twisted into pain. "Will," he said. Feeling around for her, grabbing up her body in his arms. "Willow!"

Seo went over to them. Her eyes sad.

"She's dead," Seo said. "Her head's… gone." She knelt down by Xander, a hand on his back. "I'm sorry."

A horrible, biting pain tore at Xander's face. "No…"

"She knew something," said Seo, looking back at the two Buffies. "She'd worked it out. And one of them… didn't want us to know the truth."

Xander squeezed his eyes shut. "She was the only person that I could trust," he whispered. "The only friend left in a dying world. And now… she's…"

He lay Willow's body down.

Then jumped to his feet, leaving the gun clattering onto the floor. "This is it," he decided. "Whatever game Elizabeth's playing, whatever she's trying to do with our lives, I don't care anymore." He reached into his jacket pocket.

And brought out a small, circular device.

Both of the Buffies recognized it. Their eyes going wide.

"A blanking bomb," said Xander. "From UNIT. Whatever you're planning, Elizabeth, this'll wipe it out. Wipe everything out, within a five mile radius." He primed the device, then threw it out the window. Out of reach. "Timer's counting down."

Seo stared at him. "You can't…!"

"Get your mom," said Xander, turning on Seo, "and get out." His rage was seething beneath the surface. "There's nothing left for me, anymore. No Willow. No world. No friends."

"Don't do this," Seo pleaded.

"It's too late," said Xander. "You've got a minute left. Not enough time to find and diffuse it. So move fast."

Seo swallowed, hard.

Then turned back to the two Buffies.

"Seo, you know it's me!" shouted the first Buffy. "It's Mom. You'd recognize your mom anywhere, right?"

"Just look into my eyes," the second Buffy pleaded. "You'll know. You'll see it."

Seo squeezed her eyes shut. "Quiet!" she shouted.

They both fell quiet.

Seo took a deep breath. Opened her eyes, examining both of them. "One of you was willing to destroy the world," she said, "murder Willow, and risk tearing apart the multiverse… just to get out of this Time Lock."

"Her!" both shouted, pointing at the other one.

"And that means if I choose either of you," Seo interrupted, "there's a fifty percent chance I'll introduce someone like that to my universe. The timeline I love. With the friends and family I adore." She shook her head. "I can't do that. I can't take the risk."

The Buffies stared.

"So… I'm sorry, Mom," Seo said, turning to the far wall, with the crack that linked her reality to this one. "But I can't take you back. I can't risk everyone on Earth for the sake of one person."

"What?" shouted the first Buffy. Slamming her hands on the bars. "Seo! What are you talking about?! It's me, and Xander's just set off a bomb! You'd never leave…!"

The second Buffy just gave Seo a sad smile. "It's okay," she said. "I understand. I forgive you."

Seo stopped.

A grin on her face.

"Now I know for sure," Seo said. Releasing the force field across the cells, and using her strength to bend open the iron bars. "Mom."

The first Buffy was livid. "No!" she screamed. "Seo! Stop!" She began scrambling at her own bars, trying to pull them apart. "She's tricking you! Can't you see…?!"

"She can see, that's the point," said the second Buffy, taking Seo's hand in her own. "I told you she was too smart for you, Elizabeth." She smiled down at her child. "Let's go home."

Seo smiled back at her Mom.

And reopened the portal.

"No!" screamed the other one, tearing at the bars of her prison, and lunging for Xander's dropped gun on the floor. "I won't let you get away with this! Never!"

The Crystallizer flashed.

And beside Seo, Mom cried out, stumbling with the pain of a headache, hand still clutching Seo's. As the shot from Xander's gun slammed right into Seo's back, glancing off her shoulder.

Seo tried to stifle a cry.

Xander rushed the imposter-Buffy, who was still screaming and trying to shoot. "I'll kill you for this!" she shouted. "Kill you dead! You can't…!"

Xander managed to tackle her to the floor, tossing the gun out of her grasp. "Seo, get your mom and get out of here," he said.

"Xander, I can't leave you—" Seo began.

Her mom grabbed her more firmly by the wrist. "He's right," she told Seo. "That bomb's going to go off any second. We have to get away."

Seo tried to struggle, but her shoulder was searing with pain, where she'd been struck.

"Thanks, Xander," said Mom, as she led Seo through the portal. "Thanks for everything."