The mushrooms got bigger and bigger as the three of them followed the path that Chris had found. Before long the trunks of trees were replaced by enormous stalks of fungus, and on the largest of all there was a door.
"It wasn't so far at all," said Lorna. "Much less than eight hundred years."
"This wood is a very strange place," said the Fleurlis. "Everywhere is nearer than you think, yet all of it is very far away."
"Please stop talking like that," said Lorna. "We know how you're very clever; you don't have anything to prove. Both of us are too old for riddles."
"And I'm trillions of years older than either of you. Imagine how tired of them I am! It's how this wood works, whether you like it or not."
"It's 'not'," said Lorna. "'Not's' definitely where I'm at with that."
"Nonetheless," said the Fleurlis, "we all have no choice in the matter. This door is built around a riddle, and it only opens for the right people."
"Us," said Chris. "Me and Mum."
"No," said the Fleurlis.
Lorna let out an anguished cry.
"Then what was the point of all this?" she said. "You made us have an emotional moment!"
"I'm glad we did," said Chris. "It was good."
"That's not the point, Chris. You can't go leading people around on a pointless quest. It's rude."
"It wasn't pointless," said the Fleurlis. "You aren't the right people, not yet. But you will be."
"I agree with Mum now," said Chris. "You are annoying."
"You're very close now," said the Fleurlis. "Closer than the Doctor could ever come. But you're not there yet; not quite. It has to be exact if you want to open the door. You need to answer the question to become who you need to be."
The two of them glowered at the Fleurlis.
"What is it?" said Chris, her tone making it clear she was frustrated to have to play along.
"It's very simple," said the Fleurlis. "This door. Where does it lead? Once you know that, you'll both be able to go through."
"That's not a very good riddle," said Chris. "It goes to the dome. You already told us that."
"Of course. But whose dome would it be?"
"You tell us," said Chris. "You bought us here."
"That's not how it works," said the Fleurlis. "I do know, of course— but you have to know too, and say it out loud to know that you really know it. It's just the way that everything has to be."
"Why would we know who flies around in a dome?" said Lorna. "We've hardly seen any of the universe. Shouldn't you've talked to the Doctor, and left us both safe and alone?"
"That wouldn't have worked," said the Fleurlis. "There are creatures who walk in eternity, and none of them know what lies beyond that door. But you are an adult and a child. You've both seen things they never would. And if you're both honest with yourselves, you already know where it leads."
Lorna and Chris both looked at each other awkwardly.
"I don't," said Chris. "I don't think that Mum does, either."
"Not everything's a deep psychological secret," said Lorna. "Sometimes we really don't know."
The Fleurlis was bothered by that, she saw. Suddenly he looked less confident, like he was pleading.
For the first time they both noticed it, or allowed themselves to. The black mould on the mushrooms, the strange smell of decay. How the leaves on the Fleurlis were browning, beginning to fall.
"You've never done this before, have you?" said Chris. "You've not shown yourself like this, not to the Doctor or anyone else. You've come because you're desperate. And you're scared."
The expression in his eyes was enough to confirm she was right.
"So much of this was unthinkable to me," he said. "This isn't something that any of us ever do. That's what the shape of the Dalek means for everyone; breaking rules you hadn't noticed were even there. But sometimes that's simple, all the same. It can just be allowing yourself to say what you already know."
They looked at him, now more guilty than annoyed.
"I don't suppose it's possible you brought along the wrong people?" said Lorna. "You might not've noticed it, what with having so much in your mind."
"Put it together, from the start," said the Fleurlis. "Everything you know."
Chris frowned.
"Like you said, the shape of the Dalek is coming. But that might have nothing to do with any of this."
"And the dome's about to destroy that planet," said Lorna, "and blow up the Doctor who's gone there like an idiot. And they all really love that book, though I'm not sure how they even found out about it."
"Can you tell us which planet this is?" said Chris. "It could be a bit like a clue."
The Fleurlis shook his head. "It's not somewhere whose name you'd ever know."
"Oh," said Chris. "But it must still be important. History somehow cracked and then went wrong, and this is the place that ended up in the middle. But that's not all"—
"It's not?" said the Fleurlis.
"No. This planet is firing on us, on our time. It's breaking the future and the past, and everyone's going insane. They're getting angry all through the history of the world."
Chris paused.
"But there was one thing I thought was strange"—
"Yes," said Lorna. "There was something I'd wondered about, too."
They both said what deep down they had already known.
"I'd hoped it wasn't that," said Lorna after the door had opened. "Even now. That there'd be a way to avoid what it always was."
"It's not only the Doctor that runs," said the Fleurlis. "Or who knows that they'll soon have to stop."
Chris was looking at him as the words caught in his throat, at his flaking bark and his trunk that now oozed black.
"Are you going to die?" she said.
"I'm an all-powerful being who transcends time and space. And yes, I am. It's already started."
"Then thank you," said Lorna. "We were right to trust you, here at the end."
"It's a curious thing," said the Fleurlis. "I've lived for so, so long. Even a Time Lord would balk at it. And I'm still terrified of it. I very much don't want to die."
"Then perhaps we'll remember that," said Lorna. "All of us are scared now, aren't we? However much we tried to hide it."
Chris was looking through the door with apprehensive eyes.
"I don't want to go," she said. "It's going to be terrifying."
"No," said Lorna. "But we have to anyway. Sometimes it's awful, doing right."
"Thank you," she added to the tree. "And goodbye."
She walked through the door together with her daughter, away from the smell of decay.