Chapter 11: A Thief In The Night

"Sir, I do wish you would put that down."

Tony flicked the tiny pen-like instrument between his fingers. The great inventor had taken to playing with it while he waited for JARVIS to run calculations, a habit which JARVIS most wished he would stop. It did you no good to invent amazing technology, such as a tiny arc-powered welding torch the size of a pen, if you accidentally pressed the 'on' button while playing with it, and sliced off your own fingers.

Tony, however, was not even paying attention.

He was staring at an ocean of blue.

Blue holograms, spread out a very large table in one of his tower's conference rooms, and which represented the internet traffic of Tokyo.

He was hunting for a thief. A thief that came in the night, and stole the lives of SHIELD agents. A thief who, no matter how good they were, had to leave digital footprints somewhere. There were more cameras per person in Japan than even the United States, and no foe was absolutely invisible. He hoped.

It was simply a way of finding the right angle. The right pivot, on which to turn the data, so that he could see the side of it which revealed his quarry.

He'd started, of course, with the usual places threats to world peace tended to turn up. Technology conventions, and major diplomatic or other state functions. Isolated islands with a volcano at the center. The usual. That had turned up nothing. Either the foe they faced had no interest at all in local politics, wasn't taking any interest at all in Earth's leadership, or they were missing something.

Most likely, they were missing something.

So, he had quickly turned his focus. Where could such a force stay? He'd started out with video footage taken on cellphones near the woods where SHIELD had detected the giant incursion. That had not been illuminating either. Radiating out from there, he'd started looking at everything related to any sites with fresh water, shelter, or natural resources that might be useful for an invading army. After looking at the combined data for every motel, hotel, and truck-stop halfway across Japan, he had realized he was still getting nowhere.

It was at that point he had decided to focus in on Tokyo itself. The fact that the biggest portal had emerged only a stone's throw from the capital city of one of the most advanced nations on Earth had not been a co-incidence. Well, technically it could be. Anything could be true. But it was not likely, and he needed to assume some things in order to filter through the vast amount of data he was dealing with. If he turned out to be wrong, he thought, he could always start with a different assumption, and then see where that led him. If he went through several, he might ask Dr. Banner for his ideas. Heck, he might even ask JARVIS. No, on second thought, probably not JARVIS. That thing was a technical marvel, but he'd never hear the end of it if he started asking his AI for strategic advice. Come to think of it, probably not smart to encourage his AI to start trying to model the thinking patterns of an invading army, either.

So, he proceeded on the assumption that whatever this was, it had some unique relevance to Tokyo. Not just Japan, but Tokyo in particular.

That was when he and JARVIS (mostly JARVIS, due to the limitations of human biology) had started cycling through data streams faster than a public wi-fi hotspot at the Olympics. They looked at records of every kind, from voting and school attendance to crime, disappearances, even hospital records.

SHIELD had its own medics, and very good ones too. The civilian population of Tokyo, however, did not. Moreover, they were facing significant demographic problems. After the baby boom in earlier decades, Japan's population was growing old, fast, and it was putting enormous strain on the country, certainly in terms of their economy, but also in terms of their national debt, healthcare, infrastructure... it was a silent and slow-moving national crisis, but a crisis to be sure.

Pity, then, it was not the particular national crisis that Tony Stark was looking for.

He flicked the miniature welding torch between his fingers again. There had to be something here. No invading army is invisible. Even if they were completely invisible, they'd still have to eat. To drink. To sleep. They'd still have to move around. Even if they were completely invisible, how'd they avoid bumping into people on the street, anyway?

For that matter, how did they move around without footprints? Even invisible foes leave footprints.

He sighed. "We're getting nowhere", he finally admitted. It had been hours, but so far all they had done was become experts on every other crisis that Japan had, from its vulnerability to earthquakes, to its aging population, to its problematic trade relationship with China that impeded its ability to stand up for human rights on the world stage. This was all very deep and – he thought with a yawn – utterly fascinating, but it did nothing to illuminate their current problem.

All of those problems had clear patterns in publicly (or not) available internet data. They had clear trends you could see, in terms of movements of money, people, physical assets, even newspaper reports.

What he was looking for was an invisible invasion. An invasion by something that simply did not appear to show up in any conventional set of data.

Tony threw up his hands. "Alright, forget filters. Forget patterns. Forget searching for anything in particular. Just re-process everything. Look for anything unusual. Anything. Anything at all. It doesn't matter what it is. It doesn't matter if it couldn't possibly be relevant to this. Just go through everything from Tokyo's internet traffic from now back to when the portal first opened. Look for anything which indicates an impossibly unlikely event in normal circumstances. Rank each item by how likely it is, and show me the... ten most impossibly unlikely things to have happened in Tokyo."

"Processing", came the concise yet polite voice of his AI assistant.

Tony was concerned. When he had originally accepted this assignment from SHIELD, it was a far cry from his usual Big Costumed Hero routine, yet he could not deny that he was one of the best scientists on Earth, and he had the unique advantage of a fully functional AI, JARVIS, to help him process the data.

There was also the small matter, Director Fury had said, that there were no security concerns with giving him access to SHIELD's intercept on all the internet traffic going in and out of Tokyo. "Happy to hear it", he had said, before Fury's glare had made him realize this wasn't a compliment. "Do you know why there are no security concerns with giving you access to all the internet traffic of the capital city of a G8 country?", Fury had asked icily.

That was when Tony had realized he was screwed. He simply stood there, awkward for a moment inside Fury's office. Fury, accustomed to making people sweat, had said nothing at all for a good half-minute. It wasn't often he got to make Stark truly sweat, and he was determined to enjoy every second of it. Were it not for the man's father being one of the founding members of SHIELD, and the man himself being a world-famous hero and one-man army, he'd probably have been arrested by SHIELD many times over by this point.

"The reason", started Fury, "that we are giving you access to this incredibly valuable and sensitive stream of data, is that we assume that you have, during one of your past totally illegal acts of electronic breaking-and-entry, already got access to it during one of your past breaches of the SHIELD network. Given that we assume you have already seen, or at least, gained access to this data, and it is incredibly sensitive data, letting you see it officially means we don't have to go through the nightmarish process of clearing someone else to look at it. Nor do we have to investigate or arrest you. That, and you have JARVIS, who can sort through it faster than any human."

"That, and my charming personality."

Fury did not even raise an eyebrow. "No, Mister Stark, I can, with absolute certainty, attest... that is NOT one of the reasons."

"You wound me, Director. You wound me."

"Always tempted. I have never done it yet. Yet! If, however, you cause an international incident with this data, I most certainly will. Am I understood?"

Stark ended up leaving the good Director's office with a small key fob, a security clearance device that gave him direct access to the SHIELD-controller internet backbone routers that handled Tokyo's internet traffic. It looked remarkably like the home-made forgery he'd already created back in his lab – except it had the actual SHIELD logo on it, rather than simply a small, yellow smiley-face sticker.

He wondered whether he would enjoy it when he contacted Fury to say he, the great Tony Stark, with the assistance of the most advanced AI in the world, had found... nothing. He wondered if he would enjoy the man's frustration, or whether the man would actually wound him in some way. Probably metaphorically. Hopefully. Though with Fury... you never quite know.

"Sir, I do believe I have found an interesting anomaly."

Stark snapped out of his daydream, and, with a swipe of his hand, swept all the rivers and mountains, the pouring rivers of blue data and the tall edifices of databases, off his holographic table.

"Show me."

It was not the anomaly he expected. He'd expected some sort of gigantic underground cave, big enough to hide an army (were the Japanese SHIELD agents equipped with sonar? He'd have to check that!). Even a hollow mountain would have been within his expectations at this point. Or... he dreaded to think of how much havoc you could wreak with one... an invisible hellicarrier.

Instead, facing him, stood a hologram of a man. Not a man like Bruce Banner, a mild mannered scientist who was secretly one of the most fearsome combatants on Earth, when you made him angry. No, this man looked like he had neither the brains of Banner nor the strength of the Hulk. He looked as if he had neither the style of Thor nor the experience and deadly moves of Black Widow.

The man before them looked ordinary. Extremely ordinary. Even his clothes were typical of the Japanese middle class office worker. Business attire, to be sure, but not smart enough to be an executive, nor lowly enough to be a fresh-faced intern.

It was a man indistinguishable from the millions of straight-laced office workers who called downtown Tokyo their native habitat. He stared at one of the cameras that, for JARVIS, served as eyes, and raised his eyebrow. JARVIS was not a genius inventor, though he was blessed with wit. Even he, however, knew when it was necessary to answer without snark.

The view changed. The man's skin turned transparent. You could see holographic representations of his heart, lungs... all his major organs. They shone blue, in the holographic light.

Then, bit by bit, the red appeared. At first it was only a tiny splotch, near his ankle. Soon, however, it had spread, forming secondary clusters in countless places within his body. Even his blood seemed to turn purple, fast on track to become red as well, in time.

"The most unusual thing in all of Tokyo in months is... a cancer patient?"

Tony Stark, great inventor, was staring at the man, as if willing him to turn into a second Hulk, or sprout tentacles, or suddenly shape-shift into a fish. "People get cancer every day, JARVIS. How long did he live?"

"He is still alive."

"Show me the last scan they took of him."

Instantly, the red was gone, replaced by a sea of blue. There was no cancer left, anywhere in his body.

"What you're saying is... this man was cured of terminal, endemic cancer? That's the most unusual thing?"

"I was about to, Sir, before you interrupted."

He folded his hands together, staring at the once-again-pristine blue image of a man, a man who had been given a second chance at life.

"Where is he now?"

"Unknown."

Tony's forehead knitted into a frown. He stared directly into one of JARVIS' cameras, the equivalent of looking his inhuman assistant straight in the eye.

"You're telling me that this man had terminal cancer. Progressive. Aggressive. Then one day, he's just cured. As if it was never there at all. Gets up, walks out, cured as if by magic. Now you can't find him. My AI, with access to more information than God himself, as well as all the SHIELD data from his city, cannot find him. Have you looked on the internet? Facebook? Heck, have you checked with his landlord? Hell, did you ask his mom?"

The flat, dry tone of JARVIS did not waver. "Sir, what we are dealing with here is a medical miracle. When the doctor got his scan in, they ran it twice more to be sure. They kept the man in the scanner chamber for two hours, running every test they could imagine. He was wealthy, and his doctor was, by all accounts, one of the best cancer specialists in Tokyo. He wasn't sparing expense. This doctor had been specializing in treating progressive cancers for decades, and had the backing of a well known Japanese research university. They could not believe their eyes. They only let the man out of the scanner after two hours because he screamed at them that he would break the damn thing if they did not, and those things are quite expensive. The doctor immediately called no less than a dozen colleagues to ask if they had ever, ever seen a case like this. They had not. Thereafter, the doctor made many calls to the man's home. Over thirty in the next day alone, and as many again the next day. These results caused a significant stir, but, the investigation into what caused this suddenly ran aground..."

Tony sighed again. "Because the man disappeared."

JARVIS emitted an affirmative beeping sound from a hidden speaker.

"As you say, Sir. He went completely off the grid. Withdrew his money from the bank. Told his landlady he was moving out. Left no forwarding address. In short, he pulled up all the stakes in his life and just vanished. His last medical scan shows him doing very, very well. No trace of cancer. So, its essentially impossible he just died. Something, or someone, gave him a second lease on life. His doctor wrote, in the medical file they sent across the internet to fellow cancer researchers, that it was as if he knew he was cured when he came in. He was smiling, he no longer walked as if he was in pain. He seemed like he was only coming in for confirmation of what he already knew. Once he had the confirmation... he disappeared. His doctor was enraged. Some of these messages he left on the man's answering machine, Sir, they are... quite aggressive. The doctor was convinced a cure for cancer might be found, or at least attempted, if only they could understand what cured this man. In any case, it quickly stopped because the man completely, totally vanished. He hasn't been seen or heard from by anyone, and I do mean anyone, not even the AIs that monitor social networking activity, since the day he got that exam."

Tony looked half-interested in the case. Plenty of unusual things happened every day. Certainly, a cure for cancer was unusual. Shame Stark Industries wasn't the first to invent it. Oh well. You had to leave opportunities for other scientists somewhere. Even more unusual that the patient wasn't shouting about their cure from the rooftops. But black market medicine most definitely existed, and this was just the right sort of man – rich and desperate, to give it a try. Some aggressive therapies no doubt did kill cancer – and you too, in short measure. They'd never be adopted... due to the casualty rate. Unusual, yes. Deeply weird, sure. But, not out of the realm of possibility. It would certainly explain why the man wasn't showing up anywhere. Killing cancer wasn't that hard. Killing it without also killing the patient... that was hard. There was a reason that chemotherapy drugs killed your hair and your cancer alike, and it wasn't because those drugs were especially discriminating about which cells they killed. He glanced at one of the cameras again.

"Alright JARVIS. Why do we think this is related to our invasion? What motivation would a hostile invasion force have for healing him, assuming they even could? His file says he was a wealthy banker. Money? Find some human with a deadly disease and heal him in exchange for the money they need to do things in our world? That wouldn't work..."

"Unless the invaders can assume human form, and thus acquire, and spend, our money."

Tony froze. They'd suspected that the invaders had some ability to be invisible, or at least extremely hard to detect. It was one of the last explanations for why nobody had spotted one thus far.

This, however, was like a puzzle piece falling into place. It explained why nobody had seen them. They could take human form. It also explained why nobody had seen their tracks. Their tracks, in human form, presumably looked human. It explained why they'd help a man with cancer, and why he'd disappear afterwards (eliminating a witness). It explained how they were able to move around seemingly freely, and get the drop on, even ambush, SHIELD agents without them knowing what they were dealing with. It explained a great, great deal.

That did not, however, mean it was correct. Still there is a principle: the inference to the best explanation. If you observe a puddle on the road, as well as wet grass, the natural inference to the best explanation is that it rained recently. You look to the phenomena, and you ask "what would cause this?". Then, you take your explanation, ask "what other effects would this cause?" and see if those predicted effects match what you observe. If you observe that there is a puddle, and wet grass, you infer that it must have been raining. Then you test your theory, by looking for other signs of rain, such as soft earth, and other possible causes, such as someone with a bucket throwing water around, or the presence of a water sprinkler on the grass.

Observe. Create a hypothesis. Test the hypothesis as best you can. Repeat until you have a hypothesis that explains everything you observe and stands up to repeated testing, ideally perfectly predicting the outcome of future tests you conduct based on it. Finally, you must think of a case where the test will generate a negative result – and test that too. Just to check you're not suffering from confirmation bias.

This hypothesis wasn't confirmed, or even particularly refined, but it did explain a truly alarming amount of things that were difficult to explain otherwise. It explained how the man could be cured (invader tech), why he disappeared (he was a witness), how the invaders avoided being seen (passing for human), how they moved around (as humans do), even where they might be (somewhere that requires money, and supports humans, not just an underwater cave).

"Jarvis, show me any other cases of people making unexpected recoveries from health conditions in the Tokyo area over the last... month."

The holographic man dissolved into an army of tiny men, women and children, arranged in rows like toy soldiers on a battlefield. Commander Stark, of the 1st Medical Mystery Battalion, started back at them.

"Eliminate any whose cases could reasonably be attributed to known medicine, spontaneous remission, or other such causes that could be reasonably expected. Leave only those cases that are totally unexplained."

Most of the tiny figures vanished, leaving a much smaller group. A company, not a battalion.

"Is this statistically significant?"

A map of Japan appeared, floating over the heads of the holographic figures. JARVIS' voice cut in:"This is the distribution of unexplained cases of medical remission and recovery for all health conditions in Japan over the last year."

The map contorted, areas growing, shrinking, and changing color, to indicate their relative numbers. You could pick out Tokyo, but it wasn't dominating the map any more than any other big city.

"This is the map since the portal opened."

Suddenly, the map contorted violently, with Tokyo itself turning bright red, then purple, and growing until it was almost the size of the entire rest of the country, combined. It utterly dominated the map, to the point it looked like its own nation, the other stretched and warped provinces merely islands, or protons orbiting around it.

Tony kept his eyes on the pulsing red-purple beacon that was Tokyo, as his left hand drifted towards a gizmo in his pocket.

"Call Fury", he said with a smile. "I think we just found our answer – and I just found a good reason for him to give me continued access to this data."

"Sir, you already have access to this data."

"JARVIS, shut up and make the damn call. And... don't say anything about my access to this data while I am on the call with Fury!"

"As you command", came the flat, monotone voice of the world's most patient AI assistant.