"You couldn't have been more subtle about it?" Alison asked, as they all piled into Oliver. "I mean, you practically told him that Rhys was part of your master plan!"
Seo's self-confidence had worn down, quite a lot, since she'd left William. Her face had settled into a frown, as she paced around the central console, adjusting and changing and turning.
"Not… master plan, so much," said Seo. "More of a… backup plan."
She'd already heard the news, from Dawn, about who Gray's brother was. What it meant. And why she'd sensed Jack Harkness buried under Cardiff for about 2,000 years.
She rested her hands on the top of the console. "Thing is… we all know how this ends," she said. "We've already seen it happen. Eventually, Billy turns into Bilis Manger."
"Invades your own past," Alison agreed.
"And makes Torchwood open the rift, while killing all my friends and family," Seo said. "But, of course, he's going to make one very big mistake." She turned around, eyes focused on her aunt. "He's going to kill you."
Dawn pointed to herself. "Me?"
"And if he kills you," said Seo, "none of the rest of this could ever have happened! Paradox." She shoved a lever up, and Oliver jolted back into life. "Which means… remember, with Bilis Manger, when everyone died, and then time got reversed and we all came back to life for no reason?"
"Yes," said Buffy and Alison.
"No," Dawn admitted.
"Well, turns out, we're about to cause that reversal to happen," said Seo, "by flying Oliver along the rift fractures, and letting Aunt Dawn ride out her paradox."
The ship juddered and jolted, as Dawn curled up, her head swimming, eyes watering. She sucked in a gasp of pain and confusion, before…
It all stopped.
Seo sprung forwards. Opened the doors.
To reveal a very confused-looking, one-year-younger version of Dawn, staring down at herself in bewilderment.
"Hang on," said younger-Dawn. "I think I'm supposed to be dead, or…?"
Then she caught sight of the inside of the ship. And met elder-Dawn's eyes.
"Oh, my God!" shouted the two Dawns.
"This isn't like in Harry Potter, right?" said elder-Dawn. "Where seeing yourself time traveling makes you go insane?"
"What the hell am I doing time traveling, anyways?" younger-Dawn cried. "The Doctor said doing that would make the universe go boom!"
"Calm down — everything will be fine," Seo assured the two Dawns. Turned to the younger one. "But you need a nice dose of retcon." She produced some from her pocket, and held it out to the younger Dawn. "Sorry. But elder-you remembers none of this."
Younger Dawn hesitated.
Then sighed, and swallowed down the retcon — slumping down in place, as she drifted off. Buffy and Alison dragging the sleeping younger-Dawn back inside Oliver, just to keep her safe.
Then the ground shook.
They all looked up into the sky, to discover a gigantic horned beast emerging above the city of Cardiff. Its shadow draining the life from all beneath it. Its eyes cruel and cold and deadly.
"Abaddon," Mom breathed.
"I couldn't chain Abaddon down there as tightly as I wanted," Seo admitted. Shook her head, sadly. "After all. I remembered that he was released, in my own past. I had to make that happen, again."
"But why is Billy releasing Abaddon at all?" Dawn shouted. "Billy didn't care about destroying the world! He only cared about you, Seo! So why would Billy release a monster who…?"
"It's Jack, isn't it?" said Alison. "Bilis said he'd kill anyone who came between you two, and Jack, buried beneath Cardiff, was the one who freed you from Bilis' clutches. Jack — the man who can't die."
"You think Bilis knew releasing Abaddon would make Jack sacrifice himself to stop it?" said Dawn.
"Bilis was able to predict everything else," Mom muttered. "I don't get why this would be any different."
"It's Billy's ultimate revenge," said Seo. "His ultimate plan. He wanted to enslave me to the rift, again. And he wanted to kill Jack for good."
"But if Jack's killed forever, a year back," Alison said, "he'd never have been buried beneath Cardiff in the first place!"
"Another paradox," said Dawn.
"Which is why I needed Billy to kill Rhys," Seo agreed. She gave a small grin. "We resolved Bilis Manger's paradox with the rest of us when we came forwards in time. But Jack's death is still in the future, relative to now."
"So that bit didn't get undone, when we came forwards in time," Alison realized.
"Jack's still going to die," Dawn agreed. "And he'll stay dead."
Mom turned to Seo. "You did something really smart with Rhys, didn't you?"
Seo's eyes twinkled. "Rhys was stabbed by Billy," she explained. "But when we came forward in time, that got reversed. Rhys was resurrected."
"I remember," Mom said.
"Except that Rhys is also Gwen's boyfriend," Seo continued. "Which means his resurrection will leave a lot of temporal residue on his lips. And, when he kisses her, Gwen's lips." She bounced on her toes. "Moment Gwen kisses Jack…"
"The paradox-reversal catches up with him!" said Dawn.
"And Jack springs back to life," Alison agreed. Shook her head. "Genius. Just genius!"
Mom nodded, slowly. "So… anyone here for tracking down Bilis Manger and kicking his ass?"
Seo put an arm on Mom's shoulder. Gave her a warning stare.
This was her fight. She was the one who'd been wronged. And she was the one who was going to make sure Billy got what was coming to him.
Bilis Manger, older, more worn and weary and clearly imprisoned in the rift for a very long time, appeared before them, a short time later. Looking even more insane than he had, 200 years ago.
"'Bilis Manger'," Seo mused. "Billy. Whom I met on Manger Street." Quirked an eyebrow at him. "I suppose you think that's clever."
Bilis' eyes went dark. Glaring. "I should have released myself and trapped you," he said. "I had it all worked out! I stole Alison's iPhone from the Doctor, in the 70's. Killed Dawn. Killed Rhys. Obtained your consent. Got Torchwood to open the rift." He stepped forwards, his entire body seething in fury. "So what am I missing? What?!"
Seo held up a box in her hand. That wooden-looking box in which she and Dawn had stashed that memory-altering entity — now filled with nothing but sand.
"I took it with me," Seo explained. "When I came here, from the past. That's why you couldn't find it." Then, tossing it to him, "Catch!"
Bilis caught it. Greedily grabbed at it, tearing it open, throwing both sand and box into the golden energies of the rift, where the whole thing burned away.
They all waited, with baited breath, for something to happen.
"It didn't work!" shouted Bilis Manger. "What…?!"
"It's a stasis box that I converted into a stabilizer field using a dissected iPhone," sighed Alison, from where she stood behind Seo. "All you've done, by letting the rift consume it, is to set what she's done to you in stone." Her eyes shone. "You're trapped in the rift forever, now. Sorry!"
Bilis struggled to break free from his prison. But failed.
He stared at Seo, horror flooding across him.
"As if I'd require you to kill my friends and family in order to release yourself!" Seo scoffed. She shook her head, almost disappointed in him. "The lock on your prison is empathic, you dolt. It doesn't just require you to gather items and people and have them do certain things. It requires the correct feelings behind those actions."
"What?" shouted Bilis.
"A drop of Dawn's blood — supposed to be given freely, as she forgave you," said Seo. "Alison's iPhone — a sign of trust. Torchwood's opening the rift — an expression of harmonious teamwork. Obtaining my consent — well, that goes without saying, doesn't it?"
"And Rhys?" demanded Bilis.
Seo's eyes flicked over to Abaddon, who'd noticed something in the distance. No. Some… one. Someone with more life energy than anyone else.
"Insurance," said Seo, bitterness edging her voice. "In case you worked out who actually saved me, all those years ago. And came after him." She glanced back at Bilis. "Which… looks like… you did."
Seo shot him an icy glare.
"Oh, don't bother threatening me!" said Bilis. He laughed. "Your friend Alison's already said you tricked me into keeping myself locked up here, forever. There's nothing more you can do to me!"
"That's what she said," Seo replied. A twinkle in her eye. "Not what I actually did."
Bilis' cheer fell away from him, in an instant. "What do you mean?"
Seo glanced around herself. Then leaned in, a little closer. "See, I've heard 'I think therefore I am'," she said. "But I've also heard the saying… 'if a tree falls in the forest and no one's around to hear it, does it make a noise?' Which one will win out, you think?"
Bilis started back, in alarm, as he noticed his whole body going more and more transparent. His eyes suddenly growing terrified. "No…"
"Being non-corporeal is a bit rubbish," said Seo. "Especially the way I'm doing it to you. You'll still be able to think. Still be self-aware. But no one and nothing in the outside world will ever be able to hear you, see you, or interact with you, again."
Bilis' eyes grew even more horrified. "You can't!"
Seo stepped back from him. "Imprisoning you in the rift wasn't torture, Billy," she said. "That was my way of being kind." Crossed her arms. "Not feeling so kind anymore."
Bilis' voice began to grow more and more hollow, as his body faded out of existence. "You selfish ego-maniac!" he shouted. "You torturing, murdering, lying, manipulative spoiled brat! You think you're so wonderful? You're ripped from the darkest pits of Hell, Seo! You…"
And then he disappeared.
Seo turned back to her ship, hands in her pockets. As the beast Abaddon died, in the distance, sucking the life out of a one-year-ago version of Jack Harkness, and overloading on a massive burst of life energy.
Nothing more Seo could do for him, now.
Time to get younger-Dawn back to where she belonged.
And return to Cardiff, 2009, to face everything she'd been avoiding.
It took Seo and the others five tries to actually land back on Earth. For some reason, every time Seo landed at the correct coordinates for Earth, all they saw was empty space and stars.
"But this is Earth!" Seo tried to insist. "Cardiff, 2009!"
Alison gestured out the window, at the star-scape around them. "Yeah. Looks just like it, Seo."
"Try about 20 million light years to the right," Dawn suggested. "And several million years forwards."
Seo stomped her foot. "It's Earth!" she insisted. "I landed in the right spot!" She turned back to the controls. "I… think."
"Back off, you two," said Buffy, standing beside Seo, defensively. "I mean, she's got all of time and space to navigate, here! It's okay if she gets kind of lost. And after the Sontaran thing, there's no way I'm letting her use a GPS to find her way to the…"
A stabbing pain shot through Buffy's head.
Then vanished, in an instant.
"…right planet," Buffy concluded.
What the hell were the headaches about?!
Seo tried again.
With limited success.
It was only when she made a minor temporal jump into the near-future that she managed to actually land on a planet. And the four of them arrived in Cardiff.
Buffy felt another headache, as she stepped out of Seo's ship.
But brushed it off.
Time to make sure Seo got the help she needed. Time to let Seo speak to Jack.