Here we are. The big one. The one we've all been waiting for. Thanos finally makes this play, and he'll never see Tony coming this time around. I hope I managed to do this masterpiece of an arc some small measure of justice. Let me know if I miss the mark, please.

Tony and the rest of the Avengers rode the Bifrost home, leaving Thor to deal with a traumatized bride, a brother on death row, and a long-lost sister revealed to be a megalomaniac to deal with. Hell of a way to kick off the honeymoon. Tony did not envy the Asgardian prince.

Tony quibbled and hemmed and hawed, but eventually he was forced to come clean to the team. Doping himself with Vibranium, grafting the Infinity Stones into this body, experimental nanobot injections that could (less than .01% chance, but it had been there) have eaten him alive from the inside out. Surprisingly (to him), no one called him out for having delusions of grandeur or trying to become ultrahuman out of a compulsive need for power, as he'd feared. If anything, everyone seemed put out that he'd kept the whole thing secret.

"You always had this long gunslinger act, Tony, but I'm telling you, you don't have to do this alone," Rhodey had chastened him.

Once the reality of his cyborg status and permanent jewelry was out of the way, Tony came clean about being a time traveler as well. He gave a small lecture on quantum universes and time loops and other techno/magical babble that turned everyone but Bruce into drooling zombies by the end of it. To wake them back up, Tony uploaded 'movie' versions of his memories of the old timeline, which proved quite engaging. The final tally of it was, they believed him. Natasha said she'd always suspected he was an alien or something, with the rate he came up with world-changing inventions. Cheating with time travel actually made her feel more comfortable than what she'd been thinking up.

Tony let everyone catch up on sleep, and then gave them a full security briefing on Thanos the next day. Using information divined from the Mind Stone (which consisted of Tony asking nicely and the knowledge flowing into his mind like the prophecies of a higher power) and intercepts from the galactic information network his satellites had started to pick up on and decode. It was devilishly tricky to hack a quantum-secured network, but JARVIS did it before his first cup of coffee. Tony showed them the facts and figures on Thanos and his Black Order of adopted children, how he swooped over a civilization, halved the population and indoctrinated the rest. He was the most notorious war criminal in the galaxy and was all but untouchable barring a coordinated multi-planetary assault, which of course wasn't going to happen. Politics only got even more divisive and petty when different species were involved, it seemed.

In happier news, the Iron Panacea hit the market. Tony was awarded the Nobel Prize for creating what was essentially the next step in evolution. One shot, and a person became effectively immortal, with physicality upgraded beyond even Super Serum levels and brains rewired and networked. JARVIS, FRIDAY, and Tony unofficially reigned as a triumvirate over the connected minds of humanity, supervising and smoothing out friction as more and more people everyday uploaded their very souls to the Internet. It was basically a friendly version of the Borg. People began to live out their days in vibrant, immersive virtual worlds straight out of the Matrix. In the real world, fashion extended down to what body you were wearing, as more and more advanced generations of Iron Mites were rolled out and body modification took on a whole new dimension. Extra limbs, unique colorations, you name it. Tony started up a new business called Iron Identity that hired people to spend all day coming up with and patenting original skins, which were traded among the community at a rate that boggled the mind.

Ferrinsula and New Eden (the unofficial winner of the naming sweepstakes by a significant margin) continued to schedule. Building a supercity larger than Texas took time, even with an army of builder bots and reconfigurable nanotechnology as part of the building process. Tony made sure to include a wide-open space with a couple square miles, roughly the size of the Golden City of Wakanda. This would be the battlefield for when Thanos sent his forces to kidnap/vivisect Tony and get his Infinity Stones. Afterwards, it would become an artificial jungle, his own version of Grand Central to go with the smaller parks and vegetation already integrated into each building. New Eden would be a carbon sink on a level never seen before. Tony still was tempted to go with the self-replicating Iron Mite path but continued to hold off. JARVIS and FRIDAY kept finding bugs and glitches in simulations.

Odin finally got back to Tony. Apparently, following the pleas of his wife and heir, Odin had decided against just beheading Hela and Loki and being done with it. Instead, the two were stripped of their powers and got a one-way Bifrost trip to Sakaar, a garbage planet surrounded by wormholes that really did wonky things to the local spacetime. The two apparently ended up a couple, bonding over a mutual loathing of Odin and modern Asgardian society and carving out a comfortable life as bookies for the gladiatorial matches. Tony resolved to check in on them every now and again but moved them far down on his threat index.

Odin had made a decent call, for once.

When he finally called on Tony to repay the debt owed him, Tony got permission to use the Space Stone to set up permanent portals between Earth, Asgard, and the other Nine Realms. They were all together in the Yggdrasil nebula, they should work together, and having rifts allowing permanent easy access between them all should help with that. Earth was plunged into a new age as eight (well, seven, given the extinction of the residents of Svartalfheim) other planetary civilizations were brought into close contact.

Tony accidentally achieved world peace, the nations of the world coming together to unite their resources and collectively act to present a collective front as One Humanity, One Earth. Alien technology flowed in from trade, which Tony analyzed, upgraded, and released his own versions almost as fast as the originals were introduced.

A century's worth of progress occurred in the span of 2017 alone. Technology was now advancing so fast that it boggled even the aliens. The Ancient One made an historic decision and took Kamar-Taj public, letting the world know the existence of magic and offering to teach it to any who desired and proved worthy. Tony came out as a Master, and promptly started revealing his own line of Stark Relics, inventions that had their own sentience like his beloved Cloak. The Mirror Dimension became the trash dump of the planet, with what couldn't be recycled by Iron Mites just being tossed through a portal where it wouldn't do anyone any harm. Transportation was revolutionized as a mixture of research into the Space Stone, Sling Rings, and the Bifrost led Tony and the Iron Mind to producing legit Teleportation Pads. Airplanes, trains, even cars to an extent were rendered obsolete, though they were still offered as free services for those that couldn't afford or were wary of having their molecules transplanted instantly from one place to another.

Wakanda came out of hiding, only to belatedly realize that they weren't so advanced as they thought anymore. Still, the introduction of Vibranium tech led to ever greater technological wonders for humanity.

With Earth signing a treaty with Asgard and the Nine Realms, the planet apparently passed some threshold and was deemed worthy of joining galactic society. Suddenly interstellar craft and aliens from every corner of the galaxy started to show up. Peter Quill and his ragtag band of mercenaries that called themselves the Guardians of the Galaxy popped in to visit his home planet. Tony finally got to meet Gamora, whom had died in the last timeline so Thanos could acquire the Soul Stone. She reminded him of a green Natasha. Drax was like Thor, blunt and honest and fine with the simple pleasures in life, while Rocket the racoon was like a mad scientist (well, more so than he already was) version of Tony. The Mind Stone translated Groot as well as it did any language, though it hurt Tony's head for some reason he couldn't explain. Mantis was just a sweetheart, like one of those anime girls with her big doe eyes.

Tony came to the conclusion that there was no logical reason to wait for Thanos to go get the other two Stones, especially when getting the Power Stone would involve devastating Xandar. Tony made a visit to the Nova Empire and brokered the transfer of the Orb to Tony's own hands with the Nova Prime Irani Rael (who looked remarkably like Glenn Close from back home), on the grounds that Earth could handle Thanos and wouldn't it be swell if Xandar was spared from the Mad Titan's gaze?

That done, and the Power Stone inserted into the palm of his left hand (and he thought the Space Stone had been a rush), Tony girded himself and took a visit to Vormir with a dear friend.

"Are you sure you're okay with this?" Tony asked as they climbed the mountain towards where the Stonekeeper waited.

"I have lived a life, Tony. I am ready to find peace," the Ancient One assured him. She had appointed Mordo as the new Sorcerer Supreme and accompanied Tony on his journey to acquire the Soul Stone. Theirs was a platonic love, but it was pure and true, the wise master and the grateful student. Hopefully it would prove sufficient a sacrifice for the Soul Stone.

Eventually, they came across a figure in black, sitting cross-legged in mid-air. Tony's eyes widened when he got a look at the being's face. "The Red Skull?"

The ghostly figure came to its feet. "I was known as that, once. Now I am just the Stonekeeper." The man regarded Tony. "One of only two in existence, it seems."

"I've always loved accessorizing. I just can't resist shiny things."

"You know the cost for what you seek?"

Tony, still hesitant, turned to look at the Ancient One. She smiled serenely and nodded to him.

"I do."

"Then pay it and see if the Stone deems you worthy."

Tony and the Ancient One walked hand in hand to the edge of the abyss. She gave him one last hug, and he kissed her brow. They stared into each other's eyes, saying all the words that needed saying without sound.

Then Tony hardened his heart… and gave a push.

There was a flash of orange light, Tony felt weightless and lost like he was on the Astral Plane, and he woke up in one of the pools on the barren world. An orange gem rested in his left hand.

Taking a deep breath, praying that he'd still be him once this was over, Tony reached up and pressed the stone into his bare crown, at the very top of his head where the skull was open at birth. It sank into his skin, the metallic flesh flowing like water around the singularity until it was safely nestled in the grip of Tony's scalp.

And then each of the Stones glowed and Tony arched back as infinity slammed into him.

Space. Direction and distance. The boundaries of Creation itself. The framework of dimensions.

Soul. Incorporeal essence. The essential spark of being. What brought life into the world and will leave when it ends.

Reality. Consensual existence. That which delineates between fact and fiction. Abstract and concrete simultaneously.

Time. Progress and events. The measure of existence. Past, present, future, all immutable yet flexible, nodes branching out into endless distance.

Power. Energy and force. The might locked within every quark. The impetus to rip apart or bind together if the cost was paid.

Mind. Perception and judgment. The capacity to learn. The font of intelligence, creating order out of chaos.

The components of Infinity.

United together, these six make up the universe. They ARE.

WE HAVE WAITED FOR YOU, ANTHONY EDWARD STARK.

Thanos sat on his throne in the heart of The Sanctuary II. His Black Order, those he had adopted from the planets he'd 'saved' and honed into instruments of his will, stood before him. Cull Obsidian, Ebony Maw, Proxima Midnight, Corvus Glaive. Once Nebula and Gamora had been among their ranks, but both had betrayed him. The former by trying to kill him (and very nearly succeeding, he'd trained her well), the latter by running away.

"What of the Stones?" Thanos asked.

The Maw bowed. "After the… anomaly last month, all energy signatures point to one planet: Earth."

Thanos grit his teeth. "All of them?"

The telekinetic hesitated slightly. "Yes, Mighty Father. Six signatures left Vormir that day and have since made their home with the humans. Readings suggest they all stay together at all times."

Thanos flexed the Infinity Gauntlet, which he never took off since resolving to abandon the schemes and proxies and hunt down the Infinity Stones himself. His empire had the most advanced scanners in the known universe. They could track the path of an insect on a planet's surface from a light-decade away. If this news was true, and there was no real reason why it couldn't be… it was troubling.

"So… someone beat me to it."

The sound of his flagship and mobile command center's announcement system went off. "Lord Thanos, we are being hailed."

"By whom?" he growled, curious. Who had the balls to contact him on his own vessel?

"He's calling himself Iron Man."

Thanos narrowed his eyes. The foremost of the guardians of the planet, and he suspected the holder of the Stones. Possibly possessing the powers of a God, now. "Let him through."

A holo-window opened before him. A Terran man stood facing him, tan of skin with dark hair. He wore a suit of red nano-armor, with a red cloak around his shoulders. The two somehow didn't clash. Thanos' eyes narrowed on the blue glow in the center of the man's breast. "Tony Stark, I presume."

"Mr. Harbinger of Death himself. Glad you could take my call."

"The insolence!" hissed Proxima, but Thanos held up a hand. There was no point getting worked up over disrespect.

"So, you know of me," Thanos stated rather than asked.

Stark smirked. Bringing up a finger to scratch his nose, a green glow emerged from his hand. "Oh, you and I go way back. You don't remember, but I do."

Thanos quickly caught on. "I see." Well, it was nice to know that he came close to winning in another life. "Is this so you can crow your victory in my face?"

"Oh no. Actually, I'm here to offer you an out."

"I'm listening."

"Satisfying as it would be to turn you and your whole operation to dust like that," Stark snapped, and his grin widened when Thanos couldn't help but twitch, "that just doesn't seem good enough for me. I don't just want you gone, I want you to lose. To believe so desperately you're in the right yet fail all the same. And, I'll admit, you gave me your own twisted respect last time, so I'll return the favor."

"What exactly are you proposing?"

"You and your army versus me and my army. A war to decide the fate of the universe. The whole galaxy will be watching, I already arranged it. So future generations can see the monster in the closet get vanquished or, on the off chance you win, the historic moment you 'saved' us all. One week, Earth time, from right now. I'll even promise to only use one Stone at a time."

Thanos raised a brow. "An honest fight? I didn't think you had it in you, Stark."

"Well, it's not like you have any real chance of winning. And if any of my side get hurt, I can just bring them back. Because I can do shit like that now. This is just so my conscience doesn't bother me because I didn't even give you a teeny-tiny ghost of a chance. And you're going to agree, because you know that if you don't I'll go through with just willing you into oblivion. And because, like all well-intentioned zealots, you just can't resist taking the risk you might succeed."

Thanos curled his fists. "Very well. I accept your challenge. Prepare for me to harvest the Infinity Stones from your cooling body."

A helmet appeared over Stark's face, with flat eyes and mouth that gave off a vaguely skull-like impression. "Bring it, crotch-chin."

With that, the transmission ended.

On Tony's end, he tilted his head at the JARVIS-bot holding the camera. "We done?"

"Indeed. Bravo on your delivery, Sir."

"Could have done with a better sign-off, Boss."

Tony held a hand over his heart. "Baby girl, you wound me. I worked really hard on that one."

Daya, FRIDAY's human avatar, scoffed. "I doubt that." She leaned on Jerry's shoulder, bringing up a hand to caress her bulging belly. The two already had a dozen digital children, but their first biological offspring was being awaited eagerly by its parents, siblings, and doting grandfather.

"Remind me again why we have to have this dumb fight in the first place. I thought you were out of the war business, Stark," Steve spoke up, from where he'd been watching the exchange from the side.

Tony sighed. Unbidden, the Cloak started massaging his shoulders. God, he loved that thing. It was even more appreciative since he added Vibranium stitching so it could integrate with his suit. "Simple. If I just obliterated him with my shiny new omnipotence, people would still worry that I was lying about him being gone and Thanos was still out there. A public defeat is the only way the people that flinch at his name like he's Voldemort will be able to sleep peacefully."

"If this guy's so scary, you sure we can beat him?"

"With the whole team juiced up on Iron Mites and the global military on standby?" Tony grinned. "Oh yes. And it will be glorious."

On April 27th, 2018, the Infinity War took place. On one side: Thanos, the Black Order, and a million Outriders. On the other: Iron Man (and the six Infinity Stones), Captain America, Thor, the Hulk, Black Widow, Hawkeye, Falcon, War Machine, Ant-Man, Black Panther, and 100 fully-weaponized Iron Legionnaires, with dozens of battalions from the United Nations Earth Defense Force waiting in the wings. Spiderman was forbidden from fighting, despite fervent complaints.

The battlefield was Ferrinsula, fully completed and yet deserted save for Earth's Mightiest Heroes. Camera drones from planets and news networks the galaxy over hovered around the planned battleground. Every second of footage would be analyzed for generations to come, as the most dangerous criminals and the foremost champions of justice of their generation clashed.

When the Sanctuary II entered the atmosphere, the Avengers readied themselves. Tony activated the Mark ∞, covering himself head to toe with Vibranium nanoparticles laced with enough lasers, repulsors, and shrunken ordinance (courtesy of Hank Pym, who released his formula after rescuing his wife from the quantum realm) to crack a moon. Thrusters were left out, flight being trusted to his handy Cloak of Levitation. The Infinity Stones thrummed under his skin, their energies mixing and flowing to create what he'd deemed Infinity Force, the power to fundamentally hack the universe and do whatever he wanted. He wouldn't be using it, but it was there at his fingertips if he so desired.

They fought. Thanos fell.

The galaxy rejoiced.

Tony was stuck with the bill for cleaning up all the corpses and repairing the damage to the island.

Thor brought in enough Asgardian liquor to soothe the wound.

And the Earth lived to see another day.

Yeah… it's pretty clear that I got a mixture of writer's block and loss of interest near the end, isn't it? I'm sorry to my loyal readers for the disappointment, but I figured I should at least release something instead of having this wait months for me to revisit it and get it 'right', considering the pace of my updates so far.

There will be an epilogue, where Tony finds love and we get to see the happily-ever-after's for the rest of the squad. Stay tuned for one last update, assuming the poor ending doesn't lead to an angry mob and boycott.