Martha is not a fan of the 1950s for a few reasons: the Cold War mentality settling in across the West, the whole Teddy Girl look that didn't quite work for her, and of course, the fact that it wasn't a good time to be a black woman. But while on the way to Cardassia (apparently the sunrises were gorgeous), the TARDIS had seen fit to plop them down in 1955 London, for no reason the Doctor could imagine.

"I'm sure," the Doctor said with his screwdriver between his teeth and his hands tangled up in masses of wire, "it's easy to fix." Something sparked. "Just give me-" there was a small pop! "a few minutes" and more sparks "and I'll have it good as new." Just as he finished pronouncing "new" with satisfaction, the lights in the TARDIS began flickering, then nothing but darkness.

"Or not," Martha said. "Here, I'm going to walk around a bit outside, while you fiddle some more?"

The Doctor mm-hmm'ed absently. "It shouldn't be too much of a problem. Don't wander too far off, we're not staying for long."

Martha Jones was out the door already, however, and breathing in the cold London fog. Only half a century ago, and it did seem like another world, with the fashions and the mannerisms and the signs in the windows-

"Hullo," a voice said from her left, almost startling her into a scream.

Martha whirled around to see a young woman with dark black hair and old, old eyes. Her clothes were smart, her hair pulled back, her posture straight. Rather like every one of the other passersby but for the flash of easy strength Martha saw in her eyes as she examined the TARDIS with curiosity.

"Is this new?" the woman asked. "I don't remember seeing it yesterday."

"It was built this morning," Martha fibbed, then realized she had no idea what time it was, and whether it might still be morning.

"Is that so?" the woman asked, neither believing nor disbelieving. "And did I just see you come out from inside it?"

"No," Martha said firmly. "I'm sure you must be mistaken."

"Oh I must, must I?" the woman smiled. "Well, if you say I must, I suppose I must. I must admit, I am a bit curious about it. Perhaps I shall pop inside and take a look?"

"No!" Martha said, before she could help herself.

The woman looked Martha up and down, and seemed to take in every detail, from the certainly-not-period clothing to the unconventional-for-the-times hairstyle. "Hmm," she said. "And why is it that I shouldn't pop inside and take a look?"

"Because it's not finished being built," Martha came upon in a burst of inspiration. "It could be quite dangerous. Falling beams. And sawdust. And asbestos. And who knows what else. Safer to leave it as is."

The other woman blinked twice, and chuckled. "What a sensible, realistic reason," she said, a smile playing about her lips. "I was half-expecting a door that was not what it seemed."

"Pardon?" Martha said cautiously.

"And here I was, hoping it might lead me to lands yet untraveled and worlds yet unknown," the woman laughed wryly. "You must think me very silly," she said self-deprecatingly, "but for a moment I fancied it might be a portal to another world ..."

Martha hesitated as the woman turned to leave, then spoke up. "I don't think it's silly at all," she said. "I think that's wonderful. My name is Martha Jones."

"Susan Pevensie."

"Here, I have nothing to do for a bit, so if you want to grab something to eat together, I'd love the company."

Susan smiled slowly. "I think I'd like that," she said.