The sensation of coming to after being thrown through time was not one Tony was going to cherish. His ribs ached and he must've been thrown backwards by the wave because he could feel every single one of the bruises on his back down to the last millimetre. And his head was pounding like he'd had a very intense date with a couple bottles of tequila.

He groaned and the sound just made the herd of elephants inside his skull dance more enthusiastically.

Suddenly, there were hands around his shoulders, gently manhandling him.

"Tony, how are you feeling?" he heard Rory ask. His right eyelid was gently pried apart and a small light shone into his eye.

"Like I'm not entirely sure the night before was worth it," Tony said as he tried to wave the intrusive evil light away. It really was a shame that time travel came with a lingering hangover.

Tony froze. Then his eyes flew open as he surged up. And gasped, his arms flying to support his ribs, his eyes watering with the sudden pain.

"That wasn't particularly smart," Rory mumbled, his hand coming to support Tony's back while Tony breathed through the pain. And bitter disappointment. He'd failed.

Eventually, Tony decided he needed to face reality – especially as he could vaguely hear the conversation between Amy and Rogers getting heated. It was time to face the music and figure out how much their hosts hated them and whether or not he'd destroyed their garage.

Tony took a deep breath and looked up. And up. He blinked at the clear blue sky. Carefully, he stood and turned around in a circle. They were standing in yet another non-nondescript New York alley (apparently the device had a thing for them), but just beyond the mouth of the alley, Tony could see a parking lot with a Honda Civic parked next to a blue Smart Car and, above it, a giant billboard advertising coolers using a young blonde with a cropped white top and a cowboy hat. When he faced the back of the alley and looked up then, yup, there was the ridiculously phallic-shaped space/time/whatever ship. That meant...

"I didn't fail?" He blinked again. "Wait." He looked away from the ship and back to Rory, and then over to where Steve and Amy were locked in an angry staring match, the three kids watching them through squinted, pained eyes. "Why the hell are you guys here?! The range should've been no more than three meters!"

Steve crossed his arms and straightened himself so that he could look his most imposing when he glared accusingly down at Amy. "Oh, they're not here by accident," he told Tony. "They were in the garage and snuck into the workshop just as you were turning the device on."

Amy looked entirely unimpressed by Steve's stern disapproval. She didn't roll her eyes at him, but Tony felt like it was close. "Because you're going to need our help! Whatever is going on is worse than you realize."

Timothy suddenly gasped and then pointed up to the sky. "They have spaceships in the twenty-first century?"

Amy looked over his shoulder at him, looking amused. "No, luv, that's not twenty-first century Earth technology up there. It's most likely the enemy."

"Whoever they are, they're certainly not subtle," Rory added casually.

"The enemy are aliens?!" Bethany exclaimed, her voice a few octaves higher than usual. "I thought you said the alien was a friend!"

That did make Amy roll her eyes. "Don't be silly, there are good aliens, bad aliens, and all shades in between, just like humans." Then she turned to Tony. "But we really should be getting out of here. Travelling through the time vortex leaves behind a very distinct residual radiation, one that whoever built that device of yours can no doubt scan for."

It wasn't often someone managed to flatfoot Tony with science, but nevertheless it did occasionally happen. After shaking himself mentally, he finally found the ability to reply. "Well, yeah, that makes sense and also, yes, that ship up there comes from the future or something and belongs to a guy named Kang. But the more important question, is how the hell do you know any of that?!"

Amy smirked. "That's a very long story that we don't really have time for right now. But let's just say that when I said you looked familiar it wasn't because I thought you were your father."

Now even Steve was visibly gaping. Until suddenly he wasn't anymore and the steely look was back on his face and he was looking up towards the ship.

"We've got incoming floaters," he announced.

Tony looked back and cursed as two dozen or so of them swarmed from the ship. "Well, that could be a coincidence, but I wouldn't exactly be willing to put money on it," he said.

"That's definitely a smart move," said an unfamiliar voice from the mouth of the alley.

Tony whirled around to face the newcomer.

"Who are–" Rogers began to ask, when Amy suddenly cried 'River!' and launched herself at the woman.

They embraced briefly and then pulled apart almost immediately – though Tony noticed both their eyes were slightly watery.

"Hello, Amy," said the woman with a smile. "Rory."

Rory stepped forward, his eyes had widened slightly with something akin to awe. "River," he said. "It's good to see you again." He cleared his throat. "So, I don't suppose you know how to elude those things up there."

River smirked, her eyes now dancing with mischievous delight. Her head was framed by dark blonde curls, which only enhanced the image. She looked like a daring adventurer right out of one of those pulp fiction novels Amy wrote, or maybe a sci-fi adventure movie, with her short tan leather jacket and khaki pants full of pockets and a gun slung low on each hip.

"I might have an idea or two," she said with a cocky swing of her hair. She reached into her jacket and pulled out a thin metal object, looking at it carefully as she thumbed at some sort of controls.

Beside her, Amy's eyes widened. "He gave you your own screwdriver?" she said.

Tony raised an eyebrow at the round-tipped 'screwdriver'.

"Oh, not just a screwdriver, this is his screwdriver."

River then pointed the 'screwdriver' at Kang's time-travel device and the tip lit up with a soft whirling noise. The lights on the device suddenly came on and Tony jumped back.

"What the hell are you doing?!" he demanded. "Do you even have any idea how it works?"

The woman had the gall to roll her eyes at him.

"I've reversed the polarity of the internal matrix, thus destabilizing the gravity field this particular device uses in order to enter the time vortex." The lights started blinking in random sequence. "This will flood the area with temporal radiation, thus masking our individual, much weaker signatures."

Tony blinked. "Okay, maybe you do know how it works." He refused to add the 'better than me'.

"But if you flood the area with this radiation, then won't we be covered in more of it than we already are?" Rogers asked with a frown. "Wouldn't that just make us easier to track once we're clear of the field?"

Snapping his finger, Tony pointed to him. "Captain America's got a point."

"Of course he does," River answered easily. "And, yes, it would unless we run very, very fast right... about... Now!"

The light on the tip of the screwdriver abruptly turned off just as the tiny lights on Kang's device began to flash rapidly. Tony didn't get to see what else the lights did, because then River was weaving around cars as she ran across the parking lot with them right behind her. Out of the corner of his eye, Tony saw Steve run ahead and scoop Timothy up without breaking his own long-legged super soldier-fast stride.

Behind them, there was a bright flash of light.

Tony looked over his shoulder. The floaters were skimming the top of the building just a block away.

"I hate to say it, but the chances of them not seeing us right now is pretty damn near impossible," he said as they reached the end of the parking lot and ran into yet another alley, though this one much wider and with a receiving bay to one side.

"The question isn't so much whether they can see us now, but rather whether they'll be able to figure out where we go next," Rory answered.

"Your plan is to hide until they give up?!"

Rory shrugged. "It's not my plan and I doubt that's what River's thinking."

They turned a corner and ran past yet more receiving bays. This was clearly some sort of warehouse block. Or a series of stores. Despite knowing New York really well, Tony felt lost with no idea where he was. He didn't even have his phone on him to check GPS – assuming the signal was working now.

He looked behind him. The floaters seemed to have slowed down, but were fanning out. Standard search pattern.

They rounded another corner. And stopped. The only thing in front of them was a red brick wall.

Tony heard Rogers swear violently in French and couldn't help raising an eyebrow at him despite their desperate situation. "Language, Cap."

Steve rolled his eyes and suddenly realized that neither River, nor Amy or Rory seemed worried by the dead end. He narrowed his eyes at them. As did Tony.

"Uh, you realize we're trapped here, right?" he said.

"Not even a little bit," said River cheekily as she reached for the gun on her left hip. She then pointed its oddly large, square-shaped muzzle directly at the brick wall and squeezed the trigger. A large, square of light projected onto the brick wall and the bricks shimmered for a moment before disappearing. When River lowered the gun, there was a perfect square-shaped hole in the side of the building just large enough for two people to walk through.

River flashed a smirk at Tony over her shoulder and then stepped through the hole. Tony stood there gaping while Amy and Rory quickly herded their children through and followed themselves. Then he hurried over to inspect the hole himself. There weren't any signs of heat or blasting force. It just looked as though that segment of the building had simply disappeared. When he stepped through into the office space on the other side of the wall, it was even more obvious that that was exactly what had happened. There was half a desk on one side of the hole and part of a filing cabinet on the other with a painting hanging over both with a perfect corner taken out of it.

"That's incredible," he breathed, his mind already thinking through the steps to creating such a device.

Steve stepped through the hole. "Won't this make it obvious where we've gone?" he asked.

River simply pointed her gun at the wall again and squeezed the trigger. The beam of light enveloped the empty space and it shimmered again. Seconds later, the hole in the wall was gone and the desk, cabinet and painting were back to their original forms.

"Okay, I want one of those, whatever it is," said Tony, grinning madly as he turned to River.

"Sorry, Sweety, but there are rules about that sort of thing," she said. "And we have to get going."

She holstered the magical doorway-creating gun and walked off. Tony ran after her.

"Oh come on," he whined. "That technology is amazing. Just think of the practical applications! You could, like, disappear parts of mountains in order to extract minerals and then just put them back after."

She side-eyed him. "Interestingly enough, that's exactly what the technology was originally developed for. Of course the original equipment was much larger. It wasn't until the invention of the MSR that they were able to create a portable version. The process simply took too much energy."

"The MSR?" Tony asked, suddenly more aware than ever that he and Rogers hadn't actually been introduced to River and thus he had no idea where – or when – she was from.

River took out her screwdriver and held it up. The light came on along with the familiar whirling noise. Tony couldn't read anything from the tiny screen she was staring at. After a moment she turned left down a corridor full of doors. Opening a door at the end of the corridor, River turned on a light and began walking down a set of stairs leading, presumably to the basement.

"Isn't Kang going to know about this technology?" Steve asked from somewhere behind them.

"No, the man you know as Kang the Conqueror was born in the year 3029, but the MSR wasn't invented until the 4860s," River answered easily. "Or something like that. The history of technology was never my specialty. It was definitely before the founding of New New New New New York."

"The founding of what now?!" Tony exclaimed. "Lady, who the hell are you?"

River winked at him. "Now that is a very long story indeed."

"Are you mom's alien friend with the space and time machine?" Timothy suddenly pipped up.

River suddenly stopped mid-stride. She looked down at the kid as though she hadn't even noticed him before. "No," she finally answered a few moments later, still looking stunned. "I'm his wife. Did-did you say your mom?"

She looked to Amy, who had come to stand next to Tim and put a hand over his shoulder before reaching over to pull Ben next to her. Rory came to stand by his wife with Bethany.

"You have children," River said, sounding awed. "I mean, adopted obviously."

"Yes," said Amy. "These are Timothy, Ben and Beth. Children, I'd like you to meet River Song. Your older sister."

Tony would've laughed at the way all three kids' eyes widened and their jaws dropped had he not been gaping right along with them.

Bethany was the first one to remember herself. "I thought you said your daughter died," she said quietly, the accusation clear in her voice.

"I believe the words we used were 'she was taken from us'," Rory pointed out mildly. "It's just that most people assume the person who took her was God."

"There was no God of any sort involved with what happened," Amy said darkly.

"No, but there was a hero," said River with a smile. She looked down at her new-found siblings. "A great hero. One the galaxies still tell stories about. The man who faced an unholy alliance of the most powerful religious orders the universe had to offer, who faced the demons of Demon's Run in order to take back his wife and their unborn child. The Last Centurion."

Amy smiled dreamily and batted her eye lashes at her husband. "My hero," she said.

Rory rolled his eyes. "It's not like I didn't have help," he grumbled, though the tips of his ears turned pink.

"Still, you fought headless monks with lightsabers for me," she said matter-of-factly. "That definitely counts for something."

"Your future self died for me on that alien holiday resort."

"You know part of me wants to write all this down so that I can remember to ask about it later, after I've had time to properly formulate the questions, while the other part of me wants to throw up from the mushiness," said Tony. "And I'm not entirely sure which one's winning."

Amy and Rory rolled their eyes at him in perfect unison. Tony threw his hands up in disgust.

Rogers cleared his throat. "Um, as much as I really do want to hear more, shouldn't we be going?" he asked, looking like he was trying to be stern.

River Song shook herself and then smiled brightly. "You're absolutely right!" Before she turned away, she winked once more at the kids. "By the way, when this is all over, you should definitely ask your father about the time he shoved Hitler into a storage cupboard."

There was a pause.

"Oh yeah, that did happen, didn't it?" said Rory thoughtfully.

"Dad!" Timothy exclaimed. "How do you forget something like that?!"

Rory shrugged. "Well, of all the things that happened that day it really was the least memorable."

Tony just shook his head and followed behind him. Rogers jogged up beside him and met his eyes. "You know, I never thought I'd meet anyone with a stranger life than mine," he said.

"No kidding, Spangles," Tony answered him. He frowned. "I still really want that wall-disappearing gun thing."

This time, Tony was less surprised when they stopped in front of a dead end corridor. River took a few extra seconds to calibrate something on the gun and then made another entrance into the basement of the next building – although this time they had to pass through two meters of disappeared cement foundations and dirt. They travelled through basements that weren't supposed to be connected for another half an hour, with River pausing every so often to consult her screwdriver, which was apparently more of a multi-function tool than a screwdriver.

The only explanation Tony managed to get for its multi-purpose uses was that it was 'sonic'. As if that explained everything.

And, yes, he wanted one of those too.

"So, this Kang who's causing trouble," Amy said as they walked into their umpteenth basement. "Do you know anything about him?"

River winced as she sealed up the hole she'd made. "A bit, but not much," she answered and continued talking as they hurried through yet another bland, boring structure. "The timelines are currently in flux. He's made too many big changes in them. It's dangerous."

"I know," said Amy darkly. "It's why we're here."

River's eyes widened with horror. "I thought I could feel it. How much time?"

"A few days at most."

River swallowed and took a deep breath. "Right, well, there's not really too much to say about Nathaniel Richards, or Kang the Conqueror as you know him. He's from a fairly well-off family from one of the Moon Colonies. Became obsessed with Earth and finding a way to fix Earth's atmosphere in order to make the planet habitable again. By all accounts he was quite brilliant, but I honestly have no idea where he got the time travel technology. There is no evidence of him inventing it, however according to old Moon Colony records, he did suddenly disappear for three years and when he came back he told a fantastical story about having lived in Ancient Egypt as a pharaoh. Then he started gathering followers and building an army. And now he's here."

"Have you confirmed his Ancient Egypt story?" Rory asked.

"No, but it's not entirely impossible."

"Wait, so you're saying he wants to take over the planet so that he can prevent the human race from making it uninhabitable?" said Tony in an attempt to prevent his headache from getting worse. "Because I feel like someone needs to clarify that this is a thing that apparently happens and not just some doom-saying predictions from a bunch of environmental nuts."

"I'm afraid I can't clarify anything one way or another," River answered immediately. She smirked over her shoulder at him. Again. "Spoilers."

Tony threw his arms up – and then made a pained noise as his ribs screamed at him. "But you just said Kang came back in time to prevent it from happening, which means it had to have happened in order for him to want to come back in time to prevent it!"

River was silent for a few moments. "There are a lot of things that happen in the twenty-first century. I mean, obviously history is full of important events, but the ones in the twenty-first century change everything."

She glanced at the screwdriver and then suddenly stopped beside a heavy-looking locked door with a security keypad. She pointed the screwdriver at the security keypad. As it came to life once more, she continued: "I wouldn't worry too much about Kang's motivations if I were you. In the long run it doesn't matter how noble or not they are, because should he succeed, the results will be catastrophic."

The lock clicked open and River stepped through the door open and then proceeded down yet another short corridor and then up a flight of stairs.

It was an odd sensation, walking into a hallway full of people in business suits and lab coats. Luckily, most of them seemed to be rushing around frantically and paid them no notice, but Tony felt a few curious frowns their way and knew it was only a matter of time before someone called security. Between Steve's bright-coloured costume and the Williams' 40s wardrobe, it was obvious they didn't belong.

Sure enough, a few minutes Tony heard heavy boots approaching from down the next corridor and had just enough time to note that whatever this building was, it seemed to have fairly some heavy-duty security, when River suddenly stopped in front of a door on the left and unlocked it with her screwdriver. They hurried inside and River locked it after them.

They found themselves inside some sort of lab. The walls were painted a blinding white and the floors were polished concrete. The two lab benches in the room looked fully-equipped, the metal so new it shined in the light coming in from the no-doubt hermetically-sealed windows. The smell of fresh paint and ammonia hung in the air.

River didn't give them much time to sight-see, however, and soon they were leaving the room through another hole in the wall. This time the hole led out to a small parking lot. They ran across it and in-between two other buildings. When they reached the end of the long alley, she finally stopped. Tony looked over several shoulders ahead of him and caught a glimpse of a low-lying building with several uniformed and heavily-armed guards standing in front.

No, on second glance, those men were clearly soldiers, though decidedly not US Armed Forces.

Amy, who was right behind River, gasped. "Those are UNIT soldiers!" she whispered.

"UNIT?" Rogers asked just before Tony had the chance to.

"United Nations Intelligence Task Force," said Rory. "We've worked with them before."

River turned to them with a smile. "And if you hurry, they should be able to take you to the rest of their forces." She looked up and met Tony's eyes. "By this point, the rest of the Avengers should be there as well."

Then she seemed to brace herself. "And I'm afraid this is also where I have to leave you. I really shouldn't be here at all, but I knew you'd need the hand and, well, I just couldn't shake the feeling that this was my last chance to see you."

Tony froze. He didn't like the sound of those words.

"What do you mean, you shouldn't be here?" Amy asked carefully.

River winked mischievously at her. "Well, I'm not exactly breaking the rules of time, but I am bending them a little."

"How exactly did you know we'd need help?" Rory asked as he joined the two women.

River's smile turned sly. "Spoilers," she said. Then she stepped forward and hugged them.

Amy and Rory immediately put their arms around her and each other in a tight three-way hug, clinging to each other as though they never wanted to let go. And, possibly, they didn't. Tony found himself brimming with questions about their relationship and what had happened to the three of them, but even he knew this wasn't the time for any of them.

Finally the three of them broke apart and this time Tony knew he wasn't imagining the tears glistening in their eyes.

River wiped at her eyes and then smiled brightly at her parents. "Well, I must be off now. I've got a date with a mysteriously abandoned library."

"Have fun, River," said Amy.

"And good luck," Rory added.

She smirked at both of them. "You too." She looked to the three kids standing just behind her parents. "It was good to meet you three. Take care of our parents for me, alright?"

River brought her hand up to look at the large watch Tony hadn't even noticed she was wearing and pressed a few buttons.

And then she was gone.

Tony gaped at the empty space.

"Woah!" he heard Timothy exclaim.

"Okay, forget the cool wall-disappearing gun thing," Tony finally said after a long, silent pause. "That watch is what I really want."

"Well, unless you can find a way to get to the fifty-first century, you're not getting one," said Amy. "Now come on, we've got a transport to catch."

Mentally reminding himself to revisit this entire thing later (or rather, adding it to the list of things to come back to later when there wasn't a crazy time-travelling environmental terrorist threatening the world), Tony hurried after Amy and Rory, who were already walking up to the uniformed soldiers.