To Jenny Flint’s surprise, she stepped out of the TARDIS at 13 Paternoster Row. Only… It wasn’t 13 Paternoster Row, not really. The square at the end of the street had been built up, and tall, mostly-glass buildings rose across form where the door had been, its little silver bell gone completely. In its place, all along the street, offices of dull, brown brick had sprouted up. She felt as though she ought to cry, but instead she just felt numb. Nothing lasts forever.
“Why are we ‘ere?” she asked.
“Well, this is 13 Paternoster Row,” the Doctor said. “Don’t recognize it?”
“I assume you have something else to show us, Doctor,” Vastra said.
“I do,” he replied. “Come closer. Here, take these. One each, please.” He handed them each a round little pin, which he instructed them to keep on their person at all times. The pin had a small gem in the centre, which glowed with an electric light; Jenny tried to tuck it into the pocket of her new trousers, but found that they didn’t truly exist. This troubled her more than it should have…
“And these are?” Vastra asked.
“Part of a complex, neuro-teleporational system, which transcends time and space, so try not to get them wet,” the Doctor replied, fiddling with something in his hands. When it wouldn’t respond how he wanted, he took out his sonic screwdriver, and pointed it fixedly at the device. The three pins glowed, and the device in the Doctor’s hands glowed, and the wall before them changed.
Gone were the drab bricks, the flat, boring windows. Gone was… well, everything! and slowly, in its place, the facade of 13 Paternoster Row began to materialize, just as it had been before they’d left for the future. Jenny’s eyes went wide, and her heart fluttered with something that felt like relief.
“How?” she asked.
“Temporal-Displacement Disruptor,” the Doctor said. “Very illegal in most civilized worlds. However, in 2012 Earth, they don’t know it exists yet. So technically…”
“Very clever, Doctor,” Vastra said. “The entire house?”
“It cannot be!” Stray declared. “Such a temporal displacement would take massive amounts of sustained energy! There is no way even you could generate the required..!”
“Ah, but I’m not the one generating it, Strax,” the Doctor said triumphantly. “Anyway, what’s important is that it’s here for you when you need it. Only someone with one of those pins on their person can see or interact with the house, and the TDD only works on inanimate objects, so you don’t need to worry about being carried off into a different time period. At least, not by this…”
“And no one can find us here? How clever,” Vastra mused.
“Is it really here? All of it?” Jenny asked.
“Yes,” the Doctor replied. “Clever. I suppose you don’t need the tour.”
“We’ll handle things from here, Doctor. Thank you.”
“There is… one more thing,” the Doctor said carefully. “It would be very rude of me to drop you off in an unfamiliar time with no assistance. I’d love to stay, but I have other things that need doing, so… I’ve arranged for some help. I’m told she’s the best UNIT has. I hope she won’t be a bother.”
“We shall see,” Vastra replied. “Where is she?”
“She’s meeting you here later. She’s the one who operates this,” he held up the TDD controller. “See here? Four slots, for those pins. She has the fourth. I wouldn’t presume to give her a key to your home, but she can see it an access it through the TDD if she needs to. Thought it might help.”
“Very kind, Doctor,” Vastra replied. “I think we have all we need. Would you like to come in for a cup of tea?”
“No, actually,” the Doctor replied. “There’s a certain wedding I need to be at, and I’ve a mind to make a rather grand entrance. If you don’t mind, ladies. Strax.”
With a flourish, the Doctor was gone, disappearing into his TARDIS, and the TARDIS disappearing into thin air. Jenny, Vastra and Strax turned to face the door of 13 Paternoster Row. They were home, and away. Jenny couldn’t believe it.
“Shall we?” Vastra asked, holding out her arm. Jenny took it, and they ascended the invisible stairs up to the door, and stepped inside.