The Number 22 to Putney Common tumbled out of the vortex and into real space-time, its driver gripping the steering-wheel and trying to regain control of the bus.

“Don't be so stubborn!” she yelled at it. “If we crash into something and die I shall never forgive you! Oh, my ever-giddy aunt, this could be the end.” A pause. “Stop talking to yourself, Iris,” she admonished sternly.

She sent out a distress signal on a few of the more fashionable frequencies and aimed the bus at the nearest planet. All she had to do was land in one piece, surely she could manage that? She looked out of the side window at the approaching star system. It looked awfully solid.

The Doctor, in his own TARDIS, amplified the mayday that he'd just picked up. He was afraid to breathe in case he somehow undid what was happening. He was fairly sure he was listening to a Time Lord beacon.

It was in Gallifreyan Morse and it was within fifty thousand light years and a couple of decades. He whooped with excitement and ran around the console trying to lock on to the origin of the signal.

His mind raced with the possibilities. It could be someone good, it could be someone neutral. He wasn't even especially worried if it turned out to be someone evil. He'd found another Time Lord. He wasn't alone.

Iris stepped from the bus cautiously, sniffing the air for toxins. She opened her leopard-print umbrella and stepped outside, Wellington boots squelching in the mud. She trudged around the bus, checking the damage to the exterior. Nothing much, just a few scratches, but the real problems were on the inside. The engines had been knocked out of temporal alignment and one of the gyro-pendulums had snapped off.

She could be stuck here for a very long time. She looked up at the cloudy sky and tried to pick out a silver lining. There wasn't one.

She climbed back into the bus and set the distress call to a wider range of frequencies, including a few that would never be in style at any point during the history of the universe. Then there wasn't much to do but sit about and wait to be rescued.

The Doctor clambered through the rainforest, following the bleeps of the sonic screwdriver and trying not to stand on anything lethal.

He hadn't walked very far when he saw something large and red looming through the thick lines of trees. He blinked and rubbed his eyes, because it looked an awful lot like a double-decker bus and Earth was on the other side of the galaxy.

He kept moving until he could see, clear as day, that it was in fact a double-decker bus. Not just any bus, either, it was the Number 22 to Putney Common.

“Oh,” he said.

Iris opened the door before he could knock. She stood in the doorway and looked him up and down.

“Hello, shoeface,” she said.

“Iris? What are you doing here?”

“Waiting to be rescued,” she said pointedly.

“But... how... the War, and...” His brain told his mouth to stop trying to work alone.

“I was a contentious objector,” she said, breezily. “I hid in the Obverse until it was over.”

The Doctor still wasn't entirely sure what the Obverse was. He imagined it to be something like E-Space but without the time-travelling lions. “Right,” he said, to cover his confusion. “Um. I suppose I should rescue you.”

“Where's your other half?” she asked.

He frowned. “Pardon?”

“That police box of yours. I need some spares to fix the bus and I don't have anywhere to grow them.”

“I left her over...” he looked around. “Somewhere.”

“Well, you go and bring her a bit nearer and then we can get started.”

The Doctor felt somewhat stunned. “Okay,” he said, as Iris closed the door in his face.

He parked next to the bus and left the TARDIS carrying what looked like a large microwave oven.

“Iris!” he called, unable to knock on the door because of his burden.

She helped him in with the not-a-microwave and they sat it down by the front of the bus.

“There,” he said, “portable organ-vat for a Type 40, backwards-compatible..” He wasn't sure what model the bus was, but he hoped he'd be able to grow something useful.

Iris fiddled with the controls on the front of the box. “Thanks, lovey.”

The Doctor looked at her. There she was, solid and real in her Shirley Bassey knock-off body. “You look well,” he said, trying to start a conversation.

“You look like an Easter Island statue,” she replied.

“I can explain that,” he began.

“Never mind, I prefer the version I've just made up in my head.”

She was, as ever, baffling. He'd never taken to her in previous regenerations, but maybe they could start afresh now that they were the only two Time Lords in existence. Maybe.

Iris waved him into an armchair and picked up the kettle. “How do you take your tea this time?”

“Two sugars, no lumps,” he answered. He was fidgeting with the cuffs of his jacket.

Iris switched on the kettle and looked away from it in case it never boiled. “Don't you have a human with you?”

“Not at the moment,” he said, looking a bit glum.

“What was that girl you were with last time? Daisy, was it? Petunia?”

He frowned. “Rose?”

“Yes, one of those flower names. I liked her. Bit clingy but quite bold in some ways.”

“I don't remember meeting you when I was travelling with her,” he said, looking utterly perplexed.

“Maybe it hasn't happened yet,” said Iris vaguely, not wanting to upset his sense of causality.

The kettle clicked off and picked out two teacups from the cupboard over the sink. Not her best china, of course, but not the usual everyday stuff either. She poured the tea carefully and handed the Doctor his cup and saucer. “Don't break those,” she told him.

“I'll try not to.”

He looked at her through the steam rising from his tea. He'd never been quite sure of the sequence of her regenerations, but he thought Shirley was an early one. She would have looked around forty to a human, most likely. He envied her for the wrinkles on her skin.

“So,” he said, after a while, “are we the last or have you met anyone else?”

“I almost did,” she said, “but it was just an old distress signal.” She shook her head. “It's just you and me now, my love.”

That was another thing. She wandered about the place telling people 'I've had him' but he had absolutely no memory of ever getting that close to her. He'd never wanted to get that close to her, even when she was a dead-ringer for Shirley Bassey and quite shapely with it.

He sat upright. Where had that thought come from? She was Iris Wildthyme, he wouldn't fancy her if she was the last Time Lord in the universe which, as it happened, she was. He sipped his tea awkwardly and tried to derail that train of thought.

“I'm married,” he said, a bit too hastily.

“Oh, yes, Mary-Sue Sing-Along,” she said, rather dismissively. “I was meeting you out of sequence when she was just a sparkle in a kissagram's eye.”

The Doctor translated in his head. “River Song?”

“Yes, her. How is Benny Summerfield these days?”

“How did we get from River to Benny?” he asked, confused.

Iris looked at him pityingly. “No reason,” she said.

He put his tea down on the table. “Iris, we should probably talk about what happens next.”

“What do you mean? What happens next is that you help repair my TARDIS and then I fly off to explore the universe.”

The Doctor looked at her. “I thought, maybe, since it's just us now, that you might want to travel with me,” he suggested.

“Don't be ridiculous,” she said with a cackling laugh. “Travel with you? In that old antique?”

“It's not that ridiculous,” he protested.

“You travel with me if you're so keen on clinging to me like a security blanket.”

The Doctor looked around the bus. It was slightly smaller on the inside and it smelled faintly of jasmine. “Um,” he said, not wanting to be rude.

Iris shrugged. “The offer's there if you want it.” She sipped at her tea and watched him shift uncomfortably in his seat. “I suppose you'll be wanting to impregnate me,” she said conversationally.

The Doctor choked on his tea.

“You don't have to be coy about it, Doctor, it's the obvious next step in our relationship.”

“Iris,” he said when he had finished coughing, “I have no intention of impregnating anyone.”

“Good. You're not my type. I'm not into the barely-legal look.” She thought wistfully back to earlier and later events. “I liked you when you wore velvet. And that Scottish one, I liked him. Not the sneaky little git, the other one.”

“What other one?”

“Never you mind. Besides,” she said with as much dignity as she could muster, “you only want me because I'm the last woman you can have your temporal jollies with. It doesn’t charm a girl, that.”

“Iris,” he protested, “the thought hadn't even occurred to me.” But he was going red around the ears and she could tell that he was lying.

The not-a-microwave pinged. “That'll be my parts,” she said, standing to retrieve them. “Get that magic wand out, I've lost my screwdriver down the back of the sofa.”

After a lot of work and some horrible awkward silences, they finished the job and stepped outside so she could wave the Doctor off. Iris stopped suddenly when she saw how closely he had parked beside the Number 22.

“What's your box doing to my bus?” she asked, accusingly.

“It's been ages since she's been around another TARDIS, I thought she might like the company.”

Iris huffed. “If my TARDIS has kittens I'm holding you personally responsible.”

“You do that,” he said wearily.

She touched the side of the bus. “Don't you worry, Old Thing, that blue harlot's going now.”

The Doctor looked at his own TARDIS. “Ignore her, she's jealous of your internal dimensions.”

“At least I'm not compensating for sexual inadequacies,” sniffed Iris.

The Doctor glared at her and took the TARDIS key from his pocket. “You know how to find me if you need me,” he said.

“I won't,” she said, “but it's nice of you to offer.”

The Doctor stepped forwards and wrapped her in an awkward embrace. Iris shook him off.

“Well,” he said, “if that's all you were wanting...”

“Off you go, duck. Good luck with your chin,” she added, apparently kindly.

He stepped into the TARDIS and slammed the doors shut behind him.

Iris returned to her bus, whistling a popular tune from 35th century Andromeda. That had gone quite well, all things considered. Shame he hadn't been in one of his handsome regenerations, but she'd doubtless run into one of those eventually.

She sat down in the driver's seat and started planning her next adventure.