And Afterwards, Regret
Read on AO3
The Chitauri think that Tony has potential. He’s strong and resilient, and so incredibly clever and resourceful and potentially so useful. Plans change. An ambush is planned when no one was paying close enough attention. They regret it for a long time afterward.
Tony Stark is kidnapped and it throws the whole world into chaos. He wasn’t an insignificant person by any means; everyone is panicking, people are having heart attacks all over the world, but the most affected are Tony’s friends.
Pepper takes hold of the company in an icy grip. She cannot show weakness now. There are sharks in the water, and they smell blood. Without Tony, they feel free to swarm around her. They think she is just a woman, never mind that she is the CEO of a ruthless company. Needless to say, they do not think her weak for long. She does not grieve, for to grieve would be admitting defeat. She cries, wipes her eyes, and comes back stronger. And if her eyes are colder, her smiles sharper, and her tone frigid, well, nobody dares draw attention to it. Pepper Potts does not need a man to define her. All by herself, she is enough to put the fear of God into any man's heart. But Tony is her friend, and she misses him dearly. He is all she has, but he will not be lost forever. It's her job to hold down the fort until he comes back.
Rhodey is relentless in his search. Tony is his best friend, his brother, and giving up is not in Rhodey's nature. He found Tony when he was being harassed by drunk people in a bar, he found Tony when he was throwing up on the side of the road from too many drinks and not enough sleep, he found Tony when he was passed out on the roof with tears tracks on his face, he found Tony when he was wandering the desert alone after months of searching, and he will find him now, God help anyone that tries to stop him. There is not a corner in this universe where Rhodey will not find Tony eventually.
Thor looks for Tony throughout the universe. He asks Heimdall for help, but Tony is shrouded from his eyes. He comes across rumors about a man who dared defy Thanos, a man they quickly began to call The Mechanic. Yet all his leads run cold, and no one seems to have any proof of what they say. He chases the fleeting words of drunks and thieves and finds they all lead to dead ends.
The Avengers look for Tony using everything they can. They call in any favor, and friend or acquaintance they may have, anybody that may give them even the smallest scrap of information as to Tony's whereabouts. They enlist the help of everyone they can, they run their resources dry and then some, they scrap together any hope and pour their all into it, only to find out it was hopeless in the end. They still fight the typical supervillains, but they're colder than before. They have to make up for their missing member somehow, and they do so in ruthlessness. They feel Tony's absence like a missing limb, so acutely and sharply during battles that it makes them angry, and fuels them on their path of destruction.
Tony used to do so much for this team. Without question or protest, Tony used to take care of the press, the funding, the building, the research, the cleanup. They can't understand how he handled it alone, why he never asked for help. They resolve to do everything they can to get him back if only so they can scold him for trying to do everything alone.
And yet.
Yet.
Sometimes, when too much time has passed, when they feel way in over their heads and everything has gone wrong, they dream. They dream of the attack, and they all shudder as they remember Loki and Clint, and deep in the heart of the night, when they awake in a cold sweat screaming, they can only pray that it is not too late. They don’t know if they fear or hope he is dead. They hold their breaths either way.
If Tony joins Thanos, if they manage to break him like they broke Loki, or enslave him like they did Clint, the universe is screwed. They didn't know how they didn't notice the new plan before Tony got kidnapped by that alien race with the resources and determination to make Tony into whatever they wanted. If they could make a god kneel, they could definitely break Tony down until he does whatever they want. But Tony was strong. Hope was not lost (Though sometimes it definitely felt like that).
It takes almost a year, a year of unyielding and unrelenting searching and experimenting and calling in every favor possible, a year that yields no progress, before a portal opens in front of where all the Avengers were gathered in a field after a battle, discussing their progress on getting Tony back in hushed tones.
They all hold their breath, preparing for yet another fight. A figure in a black and gold skin suit steps through, a slim figure with greasy black hair and they feel their hearts stop as they frantically search the face they barely recognize as Tony’s for unnaturally blue eyes. He’s covered in blood and dirt and is so much thinner than they remember, with circles under his eyes as dark as the cosmos behind him and it doesn’t look good; he’s carrying a severed head and he has a mad grin on his face as an army of slim black and gold suits, unlike anything he’s made before, pours out after him.
He looks up and to everyone's utter surprise, familiar soft brown eyes greet theirs, and his grin softens.
“Hey guys. Did you miss me?” he asks and tosses the severed head at their feet. Shocked, they barely manage to place it as the head of Thanos, the mad titan that was supposed to be invading earth, Tony what the hell before they look up and blink at Tony in dumbfounded shock.
It’s Steve who speaks up first, his throat suddenly dry.
“Tony...how?”
His grin sharpens into something almost feral, and they are all abruptly and unpleasantly reminded that the man standing in front of them covered in blood was once called the Merchant of Death, and for good cause.
“Simple,” Tony says as the last of his army makes it through the portal and it closes behind them, all the bots standing at attention surrounding Tony. Nobody dares draw a breath.
“My kidnappers obviously didn’t do their research, or they would’ve known what happens to people that try to kidnap me and make me build something for them.”
