The three of them stood by the police box in a universe that had fully healed. It was the Doctor's TARDIS, after all: somehow Yaz's Watcher had pulled it through. It was cool and sleek, mysterious against the world. Ready to take them somewhere strange and new.
"I came here to ask for your help," the Doctor said to Omega. "And you did give it to me. Not quite in the way I'd hoped, but"—
"You've helped me, too," said Omega. "However improbable that seemed an hour ago."
"She's all about improbable, that Doctor," said Yaz.
"I'm not sure that I ever thanked you, Omega," said the Doctor, looking out at the world. "For trying to save me, all those years ago. You suffered so much for it. And I thought you were a villain."
Omega nodded.
"Thank you," he said. "It is a long time since I have been shown kindness."
"Then you've got lots of catching up to do," said the Doctor.
"You didn't need to thank me," Omega said. "That's not why I did what I did. I tried to save you because deep down I knew it was right. Good isn't good if you're doing it for the reward."
The Doctor looked slightly shocked at that. She hesitated, weighing something up.
"You know," she said. "I wish you could come with us."
"Oh, good," said Omega. "I was worried I'd have to ask. And that wouldn't be very polite, would it? Good isn't done for the reward, but when a reward comes along, well"—
He grinned.
"It's not possible," said the Doctor. "You've been down here too long. Out there in a universe of matter? You'd explode. And you can't die, of course, so you'd reform again. Then explode. I don't think it sounds very fun."
"There's nothing for it, then," said Omega. "We'll have to go somewhere that isn't the universe. It's what I wanted anyway. I've been trapped here for so long. All of time and space?" He shook his head. "It isn't enough."
He stepped into the TARDIS with a strange smile over his face.
"I've no idea what he meant by that," the Doctor said to Yaz. "Really."
She shuffled awkwardly. She'd always find emotions difficult in this form. But that was okay. She just was who she was, till the day she'd be someone else again.
"Yaz," she said. "I was going to say. You don't have to come."
"I want to!" said Yaz. "Wherever it is that we're going."
"I'm done holding back from you," said the Doctor. "Dark times are coming to your world. What's coming, it'll need brilliant people. All the Yazes a planet can get."
Yaz nodded.
"That's what I thought," she said. "Maybe I was afraid to think it. But if there's going to be a lot of hard stuff in the future, then"—
She shrugged.
"Means I need to make time for a bit of fun," she said.
The Doctor grinned a big, stupid grin, the grin of a child who'd been given all of the sweets in the world.
"We'd best get started, then," she said.
"Box?" she asked, pointing to the open doors.
"Box," Yaz replied, absolutely affirmatively.
"Right!" said the Doctor. "Here goes! Off to see the"—
She stopped, and her grin had gone away.
"Ah," she said. "He didn't actually say where we'd be going."