Jessie grasped Jack's wrist with one hand, then reached out to get the Doctor's arm. He spared her a look, then looked to the patients. "Go to your room." Jessie blinked when they all stopped, seeming to consider him. That appeared to encourage the Doctor. "Go to your room! I mean it! I'm very, very angry with you. I am very, very cross. Go to your room!"

Jessie looked around in shock as the patients appeared to hang their heads in shame and return to their beds. She looked at the Doctor in surprise, and he let out a breath. "I'm really glad that worked," he admitted. "Those would have been terrible last words."

"Why're they all wearing gas masks?" Jessie asked.

"They're not," Jack replied. "Those masks are flesh and bone."

"How was your con supposed to work?" the Doctor asked.

"Simple enough, really," Jack replied with a shrug. "Find some harmless piece of space junk, let the nearest Time Agent track it back to Earth, convince him it's valuable, name a price. When he's put fifty percent up - oops!" Jessie rolled her eyes. "A German bomb falls on it, destroys it forever. He never gets to see what he's paid for, never knows he's been had. I buy him a drink with his own money, and we discuss dumb luck. The perfect self-cleaning con."

"Tried to get me on champagne, too," Jessie added mildly.

The Doctor threw Jack a newly furious glare. "He did what?"

"I'm not drunk or anything, if that's what you're asking," she assured him quickly. "It was just a little."

"It had better have been," the Doctor muttered. "Perfect con indeed."

"The London Blitz is great for self-cleaners," Jack told the. "Pompeii's nice if you want to make a vacation of it, though, but you've got to set your alarm for volcano day." Jessie folded her arms and fixed Jack with what Fandral and Volstagg had deemed her "Deathbringer glare." He shuffled a little. "I'm getting a hint of disapproval."

"No duh," she snorted.

"Take a look around the room," the Doctor ordered. "This is what your harmless piece of space junk did."

"It was a burnt out medical transporter!" Jack protested. "It was empty!"

"Jessie."

She walked over. "Are we getting out of here?"

"We're going upstairs."

"I even programmed the flight computer so it wouldn't land on anything living!" Jack continued to protest, and Jessie mouthed "Adam" to the Doctor, who gave her a small grin. "I harmed no one! I don't know what's happening here, but believe me, I had nothing to do with it!"

"I'll tell you what's happening." The Doctor reached the doors. "You forgot to set your alarm clock."

"Volcano day?" Jessie guessed.

"It's volcano day," the Doctor agreed.

A siren wailed overhead, and Jessie looked up. "What's that?"

"The all clear," Jack replied.

"I wish," the Doctor muttered, leaving.

"Mister Spock?" Jack called, and they ran after him.

"Doctor?" Jessie called out as well.

"Have you got a blaster?" his voice called out, and Jessie looked up the staircase to see the Doctor on the next level.

"Sure!" Jack replied as they ran up.

The Doctor looked at a metal door. "The night your space junk landed, someone was hurt," he said. "This is where they were taken."

"What happened?" Jessie asked, checking that her gun was still in the waistband of her jeans under her shirt.

"Let's find out," the Doctor replied, gesturing to Jack.

He took out a fancy-looking futuristic gun, and Jessie looked at the Doctor in surprise. "What happened to your sonic screwdriver?" she asked.

"Nothing," he replied.

Jack fired, and the lock disintegrated. The Doctor looked impressed. "Sonic blaster, fifty first century. The Weapon Factories of Villengard?"

Jack nodded. "You've been to the factories?"

"Once," he replied.

"Well, they're gone now. Destroyed. The main reactor went critical. Vaporized the lot."

"Like I said. Once." Jessie grinned at him, and he grinned back. "There's a banana grove there now. I like bananas. Bananas are good."

She snickered as he went inside the room, then looked at Jack's blaster. "Nice pattern."

"Digital," he replied.

"Squareness gun."

"Yeah."

She smirked. "SHIELD needs those for sure."

***

The Doctor looked behind him as Jack and Jessie joined them, sending Jack a warning look. "What do you think?" he asked, gesturing to the messy room.

"Something got out of here," Jessie replied, pointing to the broken window.

"And?" the Doctor encouraged.

"Something powerful," Jack suggested. "Angry."

"Powerful and angry," the Doctor agreed.

He stepped into the next room, looking at the drawings of a child scattered on the ground. "A child?" Jack asked. "I suppose this explains 'mummy.'"

"How could a child do this?" Jessie whispered in shock.

The Doctor wanted nothing more than to comfort her about that, but he turned on a tape machine instead. "Do you know where you are?" Constantine's voice asked.

"Are you my mummy?" the child asked.

"Are you aware of what's around you? Can you see?"

"Are you my mummy?"

"What do you want? Do you know - "

"I want my mummy. Are you my mummy? I want my mummy! Are you my mummy? Are you my mummy? Muuuummy? Mummy?"

"I've heard this voice before," Jessie whispered.

"Me too," the Doctor agreed.

"Mummy?"

"Always 'are you my mummy?'" Jessie continued, looking around at the drawings. "Like he doesn't know."

"Mummy?"

"Why doesn't he know?"

"Are you there, mummy? Muuuuummy? Mummy? Please, mummy. Mummy?"

The Doctor looked around oddly, and Jessie turned to him. "Doctor?"

"Can you sense it?" he asked.

"Sense what?" Jack asked.

"Coming out of the walls. Can you feel it?"

"Mummy?"

"Funny little human brains," the Doctor commented, looking around some ore. "How do you get around in those things?"

Jessie grinned. "When he's stressed, he likes to insult species."

The Doctor threw her a look. "Jessie, I'm thinking."

She laughed. "Cuts himself shaving, he does half an hour on life forms he's cleverer than. Always does."

The Doctor glared at her, but she kept on giggling for a while until he continued. "There are these children living rough round the bomb sites. They come out during air raids looking for food."

"Mummy, please?"

"Suppose they were there when this thing, whatever it is, landed?"

"It was a med ship," Jack repeated, and Jessie pinched the bridge of her nose in exasperation. "It was harmless!"

"Yes, you keep saying harmless," the Doctor replied. "Suppose one of them was affected. Altered?"

"Altered how?" Jessie asked.

The tape ran out, but the voice continued. "I'm here!"

"It's afraid," the Doctor said. "Terribly afraid . . . and powerful. It doesn't know it yet, but it will. It's got the power of a god." His eyes widened a little in understanding. "And I just sent it to its room."

"Doctor?" Jessie asked softly.

"I'm here. Can't you see me?"

"What's that noise?" she asked.

The Doctor swallowed, looking at her. "End of the tape. It ran out about thirty seconds ago."

"I'm here now. Can't you see me?"

"I sent it to its room," the Doctor said slowly, turning. "And this is its room."

He turned to see the child right behind them.

***

"Are you my mummy?" the child asked. "Mummy?"

"Doctor?" Jessie asked slowly, reaching behind her back for her gun.

"OK," Jack said, reaching for his own gun. "On my signal, make for the door."

"Mummy?"

"Now!" Jack shouted, drawing his gun.

And Jessie burst out laughing when he came out with a banana instead of a gun.

The Doctor grinned as well, revealing the gun he had hidden, and he blasted a square hole in the wall. "Go now!" he shouted. "And don't drop the banana!"

"Why not?!" Jack asked in annoyance as Jessie darted through.

"Good source of potassium!" the Doctor replied, and Jessie cracked up again.

"Give me that!" Jack snapped as they all made it through, and sealed the hole back up. Jessie was still laughing, and both men glared at her.

"It's from the groves of Villengard," the Doctor explained, taking back his banana. "I thought it was appropriate."

"There's really a banana grove in the heart of Villengard, and you did that?" Jack asked.

The Doctor shrugged. "Bananas are good."

The wall cracked, and Jessie's eyes widened. "Doctor!"

"Come on!" They ran in the other direction, but were stopped by the patients marching through, all saying "mummy." The Doctor held out an arm, and Jessie stumbled into it. "It's keeping us here till it can get at us."

"It's controlling them?" Jack asked.

"It is them," the Doctor replied grimly. "It's every living thing in this hospital."

Jack began rattling off. "OK. This can function as a sonic blaster, a sonic cannon, and as a triple-enfolded sonic disrupter." Jessie snorted in amusement. "Doc, what you got?"

"I've got a sonic - " He paused, and Jessie giggled a little. "Oh, never mind."

"What?" Jack persisted.

"It's sonic, OK? Let's leave it at that."

"Disrupter?" Jack demanded. "Cannon? What?"

"It's sonic! Totally sonic! I am sonicked up!"

Jessie burst out laughing at that. "A sonic what?" Jack shouted.

"Screwdriver!" the Doctor barked.

Jessie rolled her eyes, and then the child broke through the wall. "Going down!" she warned, gripping both men's arms, phasing them through the floor.

They flew down, Jessie bending her knees in preparation for hitting the floor. She bounced up immediately afterwards, then looked at the Doctor in worry. "Doctor? You OK?"

"Could've used a warning," he grumbled in reply.

She rolled her eyes. "Oh, I can feel the gratitude," she muttered, rolling her eyes.

"Who has a sonic screwdriver?" Jack asked, standing up as well.

"I do!" the Doctor replied.

"Lights . . . " Jessie murmured, searching the walls.

"Who looks at a screwdriver and thinks, 'ooh, this could be a little more sonic?'" Jack continued.

"What, you've never been bored?" the Doctor asked.

"There's got to be a light switch." Jessie continued her search.

"Never had a long night? Never had a lot of cabinets to put up?"

Jessie finally found the light switch and flicked it on, and as if on cue, the patients all sat upright, all with cries of "mummy."

"Door!" Jack called, trying his blaster, but it didn't work. "Damn it!" Jessie raised an eyebrow at him as the Doctor finally pulled out his sonic screwdriver, working on the lock. "It's the special features. They really drain the battery."

"Battery?" she squeaked as they made it into the storeroom on the other side of the door. "That's so lame!"

"I was going to send for another one, but somebody's got to blow up the factory!" Jack exclaimed, glaring at the Doctor.

"Trust me, first day I met him, he blew up the department store I was trapped in," she assured him. "That's pretty much how he communicates."

"OK!" the Doctor said, backing away from the door. "That door should hold for a bit."

"The door?" Jack repeated in disbelief. "The wall didn't stop it!"

"Well, it's got to find us first! Come on, we're not done yet! Assets, assets!"

"Got a gun, Night Night pistol in my boot, can phase through anything, fire and air," Jessie rattled off.

"And I've got a banana," Jack continued, "and in a pinch, you could put up some shelves."

The Doctor bounced up to a window. "Window."

"Barred," Jack replied. "Sheer drop outside. Seven stories."

"And no other exits," Jessie finished.

"Well, the assets conversation went in a flash, didn't it?" Jack asked.

"So where'd you pick this one up, then?" the Doctor asked sarcastically.

"Hey!" Jessie protested.

"She was hanging from a barrage balloon," Jack replied casually, and the Doctor blinked in surprise. "I had an invisible spaceship. I never stood a chance."

"OK," he commented before going back to the window. "One, we've got to get out of here. Two, we can't get out of here. Have I missed anything?"

"Uh, yeah," Jessie replied, looking at where Jack had just disappeared. "Jack's gone."

The Doctor looked over his shoulder to see that the con man had indeed disappeared. He rolled his eyes. "Great."

"OK," Jessie began slowly, sitting down in a chair and leaning back. Let's have some fun. "So he's vanished into thin air. Why is it always the great looking ones who do that?"

The Doctor looked at her in surprise to see her sly look as she looked up at him. "I'm making an effort not to be insulted," he informed her.

She threw him a smirk. "I mean men."

The Doctor rolled his eyes, and Jessie knew that he was now sure that she was just toying with him. "OK, thanks. That really helped."

The radio in the corner crackled. "Jessie? Doctor? Can you hear me?" Jack asked. "I'm back on my ship. Used the emergency teleport. Sorry I couldn't take you. It's security-keyed to my molecular structure. I'm working on it. Hang in there."

"How're you speaking to us?" the Doctor asked in surprise.

"Om-Com. I can call anything with a speaker grill."

"Now there's a coincidence," the Doctor muttered.

"What is?"

"The child can Om-Com, too."

"He can?" Jessie asked in surprise.

"Anything with a speaker grill. Even the TARDIS phone."

"What, you mean he can phone us?" Jessie asked.

"And I can hear you," the voice of the child came in on cue. "Coming to find you. Coming to fiiiiiiind you."

"Doctor, can you hear that?" Jack asked.

"Loud and clear," the Doctor replied.

"I'll try to block out the signal. Least I can do."

"Coming to find you, mummy."

"Remember this one, Jessie?"

Moonlight Serenade came through, and the Doctor raised an eyebrow as Jessie burst out laughing. "I don't even want to know," he muttered.

She reclined further in the wheelchair, watching as he worked at the bars with his sonic screwdriver. "What're you doing?"

"Trying to set up a resonation pattern in the concrete," he replied. "Loosen the bars."

Jessie smiled. "You don't think he's coming back, do you?"

"Wouldn't bet my life," was the immediate reply.

"Why don't you trust him?"

"Why do you?"

Jessie shrugged. "He saved my life." She grinned, deciding to have some more fun. "Guy wise, that's up there with flossing. I trust him because he's like you." She looked at her nails casually. "Except with dating and dancing."

"You just assume I'm - "

Jessie looked up, smirking. He had gone still, and she giggled a little. "What was that?"

"You just assume that I don't dance," he replied.

She grinned. "What? You're telling me you dance?"

"Nine hundred years old, me. I've been around a bit. I think you can assume at some point I've danced."

"You?"

The Doctor snorted. "Problem?"

"Doesn't the universe implode or something if you dance?" she joked.

"Well, I've got the moves, but I wouldn't want to boast," he replied.

Jessie smirked, knowing that he'd fallen right into her trap. She reached over to the radio and found the volume knob, and she turned it up. "You've got the moves?" she asked, standing up. "Show me your moves."

The Doctor spared her a look, but he just as quickly turned back. "Jess, I'm trying to resonate concrete."

"Jack'll be back," Jessie assured him. "He'll get us out. So come on. The world doesn't end because the Doctor dances."

He shot her another look, but he jumped off of the desk he was standing on and walked over. He pulled her close, and she didn't mind if it was a little closer than usual. He took a look at the hand he was holding, then frowned. "Barrage balloon?" he asked.

"What?"

"You were hanging from a barrage balloon."

"Oh, yeah," she replied nonchalantly, like she was talking about the weather. "About two minutes after you left me. Thousands of feet above London, middle of a German air raid, and I've got the Union Jack all over my chest."

"I've traveled with a lot of people, but you're setting new records for jeopardy friendly."

"This you dancing?" Jessie teased lightly, nudging his leg with her boot. "Because I've got notes."

The Doctor ignored her. "Hanging from a rope thousands of feet above London." He ran his thumbs over her palms, and she couldn't hold back the shiver that went down her spine. "Not a cut. Not a bruise."

"Yeah," she replied. "Captain Jack fixed me up."

He raised an eyebrow. "Oh, we're calling him Captain Jack now, are we?"

"Well," Jessie said slowly, smiling so she could tease him a little more. "His name's Jack, and he's a Captain."

"He's not really a Captain, Jess."

"Y'know? I think you're experiencing Captain envy." She smirked. "Also, your feet are on the end of your legs. Feel free to move them."

"If he ever was a Captain, he's been defrocked."

"Shame I missed that."

"Actually," Jack's voice commented from behind them. "I quit. Nobody takes my frock. Most people notice when they've been teleported." Jessie jumped in surprise, looking around at the interior of Jack's ship. The Doctor jumped away as well. "You guys are so sweet. Sorry about the delay. I had to take the nav-cam offline to override the teleport security."

"You can spend ten minutes overriding your own protocols?" the Doctor asked. "Maybe you should remember whose ship it is."

"Oh, I do," Jack assured him. "She was gorgeous. Like I told her. Be back in five minutes."

"This is a Chula ship."

"Yeah, just like that medical transporter. Only this one is dangerous."

The Doctor snapped his fingers, and a golden mass appeared around his hands. Jessie nodded. "Those fixed my hands. Jack called them . . . uh - "

"Nanobots?" the Doctor suggested. "Nanogenes."

"Nanogenes," Jessie replied. "Yeah."

"Sub-atomic roots," the Doctor explained. "There's millions of them in here, see? Burned my hand on the console when we landed." He held up one. "All better now. They activate when the bulk head's sealed. Check you out for damage, fix any physical flaws." He looked at Jack. "Take us to the crash site. I need to see your space junk."

"As soon as I get the nav-cam back online," Jack replied. "Make yourself comfortable." He smirked at Jessie. "Carry on with whatever it was you were doing."

"We were talking about dancing," the Doctor commented lightly.

"It didn't look like talking," Jack pointed out.

And just because she couldn't help it, Jessie muttered, "It didn't feel like dancing."

***

A while later, the three of them ran lightly towards the crash site. "There it is," Jack told them, pointing. He narrowed his eyes. "Hey . . . they've got Algy on duty. It must be important."

"We've got to get past him," the Doctor said.

Jessie looked at him. "Are the words 'distract the guard' heading towards me?"

"I don't think that'd be such a good idea," Jack told her.

"You saying I can't handle it?"

"I've got to know Algy quite well since I've been in town. Trust me, you're not his type. I'll distract him. Don't wait up."

Jessie sighed, watching Jack run over to the guard. "Good Lord."

"Relax," the Doctor told her. "He's a fifty first century guy. He's just a bit more flexible when it comes to dancing."

"How flexible?" Jessie asked.

"Well, by his time, you lot have spread out across half the galaxy."

"Meaning?"

"So many species, so little time."

"What, that's what we do when we get out there? That's our mission?" Jessie asked incredulously. "We seek new life, and - " She cut off, flushing a little. "And . . . "

"Dance," the Doctor finished, smirking at her.

A commotion down by Jack stopped them, and Jessie looked just in time to see Algy fall to his knees, face turning into a gas mask. They ran over, the Doctor shouting "Stay back!" to anyone who'd listen.

"You men, stay back!" Jack added to everyone else.

"The effect's become airborne, accelerating," the Doctor explained.

Jessie looked up when the air raid sirens came back on. "What's keeping us safe?" she asked.

"Nothing," the Doctor replied.

Jack looked up, hearing the planes go by. "Ah. Here they come again."

"All we need," Jessie grumbled, then looked at Jack. "Didn't you say a bomb was going to land here?"

"Never mind that," the Doctor told her. "If the contaminant's airborne now, there's hours left."

"For what?" Jack asked.

"Till nothing, forever," the Doctor replied. "For the entire race." He frowned, tilting his head. "And can anyone else hear singing?"

Jessie waited as he went off for a while, then raised an eyebrow when he came back with a young dark-haired woman. "Hello."

"Nancy, this is Jessie and Jack," the Doctor introduced them as they ran towards the spacecraft. "Jessie, Jack, meet Nancy."

"You see?" Jack asked as they uncovered the craft. "Just an ambulance."

Nancy raised an eyebrow. "That's an ambulance?"

"Hard to explain," Jessie told her apologetically. "It's from another world."

"They've been trying to get in," Jack explained.

"Of course they have," the Doctor replied. "They think they've got their hands on Hitler's latest secret weapon." He narrowed his eyes as Jack punched in a code. "What're you doing?"

"The sooner you see this thing is empty, the sooner you'll know I had nothing to do with it," Jack replied.

Jessie jerked backwards as sparks flew from the access panel, along with a sharp bang. An alarm began going off, and she pointed at the red light flashing. "Nice job, Jack."

"Didn't happen last time."

"It hadn't crashed last time," the Doctor pointed out. "There'll be emergency protocols."

Jessie looked up when a banging noise sounded. "Doctor, what is that?" she asked, then jumped when she saw the hospital doors begin rattling. "Doctor!"

"Captain, secure those gates!" the Doctor ordered, pointing.

"Why?" he asked.

"Just do it!" the Doctor snapped, then turned to Nancy. "Nancy, how'd you get in here?"

"I cut the wire," she replied.

"Show Jessie." He turned to Jessie. "Setting 2428D."

Jessie caught the sonic as he threw it to her. "What?"

"Reattaches barbed wire. Go!"

***

Jessie kneeled on the ground, fixing the wires as Nancy held them together. "Who are you?" Nancy asked. "Who are any of you?"

Jessie smiled at her. "You'd never believe me if I told you."

"You just told me that was an ambulance from another world," Nancy pointed out. "There are people running around with gas mask heads calling for their mummies, and the sky's full of Germans dropping bombs on me. Tell me, do you think there's anything left I couldn't believe?"

Jessie shrugged. "We're time travelers from the future."

"Mad, you are," Nancy immediately said.

Jessie chuckled. "We have a time travel machine. Seriously!"

"It's not that," Nancy assured her. "All right, you've got a time machine. I believe you. Believe anything, me. But . . . what future?"

Jessie sighed, holding the girl's hands. "Nancy, this isn't the end. I know how it looks, but it's not the end of the world or anything."

Nancy looked at her incredulously. "How can you say that? Look at it!"

"Listen to me," Jessie told her. "I was born in the States, but London's been my home for years now. I'm here in, like, fifty years time."

"Here?"

"Yep. From your future."

"But," Nancy stuttered. "But you're not - "

"What?"

"German."

Jessie chuckled. "Nancy, the Germans don't come here. They don't win. Don't tell anyone I told you so, but you know what? You win."

"We win?" Nancy asked.

Jessie looked up, hearing the sound of bombs come closer. "Come on!"

***

"It's empty," Jack was saying as they got back. "Look at it!"

"What do you expect in a Chula medical transporter?" the Doctor asked. "Bandages? Cough drops?" He turned to Jessie. "Jess?"

"I don't know."

"Yes, you do."

And she had it. "Nanogenes!"

"It wasn't empty, Captain," the Doctor told Jack. "There was enough nanogenes in there to rebuild a species."

And Jack got it, too. "Oh, God."

"Getting it now, are we?" the Doctor asked. "When the ship crashes, the nanogenes escape. Billions upon billions of them, ready to fix all the cuts and bruises in the whole world. But what they find first is a dead child, probably killed earlier that night, and wearing a gas mask."

"And they brought him back to life?" Jessie asked incredulously. "They can do that?"

"What's life?" the Doctor asked, pacing. "Life's easy. A quirk of matter. Nature's way of keeping meat fresh. Nothing to a nanogene. One problem, though. These nanogenes, they're not like the ones on your ship," he told Jack. "This lot have never seen a human being before. Don't know what a human being's supposed to look like. All they've got to go on is one little body, and there's not a lot left. But they carry right on. They do what they're programmed to do. They patch it up. Can't tell what's gas mask and what's skull, but they do their best. Then off they fly, off they go, work to be done. Because, you see, now they think they know what people should look like, and it's time to fix all the rest! And they won't ever stop. They won't ever, ever stop. The entire human race is going to be torn down and rebuilt in the form of one terrified child looking for its mother, and nothing in the world can stop it!"

"I didn't know!" Jack protested weakly.

The Doctor checked the ambulance. "Jessie!" Nancy cried out as the patients began approaching.

"It's bringing the gas mask people here, isn't it?" Jessie asked, wrapping an arm around Nancy as they backed up.

"The ship thinks it's under attack," the Doctor confirmed. "It's calling up the troops. Standard protocol."

"But the gas mask people aren't troops!"

"They are now. This is a battlefield ambulance. The nanogenes don't just fix you up. They get you ready for the front line. Equip you, program you."

"That's why the child's so strong," Jessie guessed. "Why it could do that phone thing."

"It's a fully equipped Chula warrior, yes," the Doctor confirmed. "All that weapons tech in the hands of a hysterical four year old looking for his mummy. And now there's an army of them."

"Why don't they attack?" Jack asked.

"Good little soldiers," the Doctor replied. "Waiting for their commander."

"The child?" Jack asked.

"Jamie," Nancy whispered.

"What?" Jack asked.

"Not the child," she replied fiercely. "Jamie."

"How long until the bomb falls?" Jessie asked.

"Any second," Jack replied tensely.

"What's the matter, Captain?" the Doctor asked. "A bit too close to the volcano for you?"

"He's just a little boy!" Nancy told them.

"I know," the Doctor replied.

"He's just a little boy who wants his mummy."

"I know. There isn't a little boy born who wouldn't tear the world apart to save his mummy. And this little boy can."

"So what're we going to do?" Jessie asked.

The Doctor slowly shook his head. "I don't know."

"It's all my fault," Nancy whispered in shock.

"No," the Doctor told her.

"It is," she argued. "It's all my fault!"

"How can it be your - " the Doctor started, then froze. "Nancy, what age are you? Twenty? Twenty-one? Older than you look, yes?"

Jessie got it, and her eyes widened. "Doctor, that bomb," Jack told them. "We've got seconds."

"You can teleport us out," Jessie suggested.

"Not you guys," he replied. "The nav-com's back online. Going to take too long to override the protocols."

"So, it's volcano day," the Doctor replied. "Do what you've got to do."

"Jack?" Jessie asked.

The Captain vanished as the Doctor turned back to Nancy. "How old were you five years ago?" he asked. "Fifteen? Sixteen? Old enough to give birth, anyway. He's not your brother, is he? A teenage single mother in 1941. So you hid. You lied. You even lied to him."

Jessie looked up as the gates open, and Jamie approached. "Are you my mummy?" he asked.

"He's going to keep asking, Nancy," the Doctor told her. "He's never going to stop."

"Mummy?"

"Tell him. Nancy, the future of the human race is in your hands. Trust me, and tell him."

Nancy swallowed and began to walk towards Jamie. The Doctor grasped Jessie's arm and pulled her close. She pressed herself closer to him, hoping desperately that this worked.

"Are you my mummy?" Jamie asked. "Are you your mummy? Are you my mummy?"

"Yes," Nancy replied. "Yes, I am your mummy."

"Mummy?"

"I'm here."

"Are you my mummy?"

"I'm here."

"Are you my mummy?"

"I'm here."

"Are you my mummy?"

"Yes," Nancy whispered.

"Are you my mummy?"

"He doesn't understand," the Doctor realized, and Jessie put a hand over her mouth. "There's not enough of him left."

"I am your mummy," Nancy told Jamie fiercely. "I will always be your mummy. I'm so sorry. I am so, so sorry."

Jessie watched as Nancy hugged Jamie tightly, and she gasped as the nanogenes surrounded the two of them. "What's happening?" she asked. "Doctor, it's changing her! We should - "

"Shush!" he told her, then approached the two cautiously. "Come on, please! Come on, you clever little nanogenes. Figure it out! The mother. She's the mother! It's got to be enough information. Figure it out!"

"What's happening?"

"See?" He gestured as the nanogenes disappeared. "Recognizing the same DNA." Jamie let Nancy go, and she stumbled onto the ground, and the Doctor approached more. "Oh, come on!" he pleaded. "Give me a day like this. Give me this one!" The Doctor lifted Jamie's gas mask, and Jessie grinned widely. "Ha ha!" the Doctor laughed, hugging the boy. "Welcome back! Twenty years till pop music! You're going to love it!"

"What happened?" Nancy asked.

"The nanogenes recognized the superior information. The parent DNA. They didn't change you because you changed them! Ha ha! Mother knows best!"

"Oh, Jamie!" Nancy breathed, hugging him tightly.

Jessie looked up, hearing the bomb get closer. "Doctor! That bomb!" she warned.

"Taken care of it."

"How?"

"Psychology."

Jessie braced herself automatically for the bomb to hit, but it got caught in the middle of a light beam instead. She laughed when she saw Jack sitting it straddle style. "Doctor!" he called.

"Good lad!" the Doctor shouted back.

"The bomb's already commenced detonation. I've put it in stasis, but it won't last long!"

"Change of plan. Don't need the bomb. Can you get rid of it, safely as you can?"

"Jessie?"

She looked up at the con man. "Yeah?"

"Goodbye." He disappeared, but popped back a moment later. "By the way . . . love the T-shirt!"

She chuckled as both he and the bomb disappeared. Her attention was drawn back to the Doctor, who stepped forward and summoned the nanogenes. "What're you doing?" she asked.

"Software patch," he replied, looking at the nanogenes. "Going to email the upgrade." He grinned at her. "You want moves, Jess? I'll give you moves." He threw the nanogenes into the patients, and they all fell to the ground. "Everybody lives, Jess. Just this once. Everybody lives!"

***

"So, history says there was an explosion here," the Doctor commented as they walked away towards the TARDIS after saying goodbye to Nancy and Jamie. "Who am I to argue with history?"

Jessie raised an eyebrow at him pointedly. "Usually the first in line."

He nodded in acknowledgement and unlocked the TARDIS. "By the way, here's yours back." She accepted her key back, smiling when she saw that the chain was newer and finer. "So, the nanogenes will clean up the mess and switch themselves off, because I just told them to." He danced around the console. "Nancy and Jamie will go to Doctor Constantine for help. Again, ditto. All in all, all things considered . . . fantastic!"

"Look at you," Jessie laughed. "Beaming away like you're Father Christmas."

"Who says I'm not, red bicycle when you were twelve?"

Jessie's jaw dropped. "Say what now?"

"And everybody lives, Jess! Everybody lives!" He grinned. "I need more days like this."

"Doctor?"

"Go on, ask me anything!" he encouraged, grinning and folding his arms. "I'm on fire!"

"What about Jack?" she asked, and the Doctor slowly nodded, realizing what she was getting at. "Why'd he say goodbye?"

"Who says we have to?" the Doctor asked, flipping switches on the console. "And I'm pretty sure I owe you a dance."

Jessie grinned in delight as Moonlight Serenade began playing. As the Doctor made the TARDIS materialize in Jack's ship, they tried to figure out how to dance. The first few attempts mainly ended up with them laughing, and Jessie poked her head up over the console to see Jack looking at them in astonishment. "Hurry up, Jackie boy!" she shouted, and he ran in without arguing. She turned back to the Doctor, a smile on her face. "OK. And right and turn." They moved through it, and she burst out laughing again. "OK, OK, try and spin me again, but this time, don't get my arm up my back. No extra points for a half-nelson."

"I'm sure I used to know this stuff," he grumbled, and Jessie just giggled. He pointed to Jack. "Close the door, will you? Your ships about to blow. There's going to be a draught." Jack did just that, and the Doctor sent the TARDIS engines running. "Welcome to the TARDIS!"

"Much bigger on the inside," Jack commented.

"You'd better be," the Doctor retorted.

"I think what the Doctor's trying to say is, you may cut in," Jessie teased, walking over.

"Jess!" he suddenly exclaimed. "I've just remembered!"

"What?"

The music changed from Moonlight Serenade to In The Mood, and Jessie burst out laughing. "I can dance!" the Doctor crowed. "I can dance!"

"Actually, I thought Jack might like this dance," Jessie suggested.

"I'm sure he would, Jessie," the Doctor agreed. "I'm absolutely certain. But who with?"

Jessie laughed, and Jack nudged her. "Go," he told her. "I got the message. Hands off the brunette."

Jessie ran to the Doctor's side. He caught her halfway and sent her in a twirl. She squealed in surprise, and he chuckled. They kept dancing a little, and Jessie thought he was right. He did know how to dance. In this style at least. He caught her when she spun yet again, and she laughed in delight when he dipped her.

And when he brought her back up, their faces only inches apart with Jack applauding, she didn't mind one bit. The world doesn't end if the Doctor dances, she thought happily.

***

TARDIS trio is officially formed! I loved Jack and Nine in this episode. "Sonic what?" "I am totally sonicked up!"

I always love it when they try showing off for Rose. It's always going to be the Doctor for her. And it looks like Jessie might be thinking in the same direction. She's getting a little braver. ;)

Interlude's up next!