A few hours later, they had located a man suspected of dealing in stolen vibranium in South Africa. Usually, Tony would sit next to Bruce and talk with him during long trips on the quinjet, but this time, Bruce didn't even look at him as they got on the plane.

Tony tried not to let it bother him and focus on the mission, but he couldn't. They had been together for almost three years, and this was the first big fight they had ever had. Of course, they had argued about little things like Tony staying up for days in his workshop or whether they really had to go to Steve's mandatory team bonding sessions, but this was so much worse. He hadn't meant what he said to Bruce, he was just so thrown off by Ultron, and the judgments from the team only made him feel more guilty. Bruce was right, after all. Ultron was his fault.

When they exited the jet in Johannesburg, Tony tried to stay behind to talk to Bruce, but Natasha was still there, handing him an earpiece.

"We'll call you if there's a Code Green."

Bruce nodded and turned around quickly to sit in the back of the jet.

When Bruce woke up on the helicarrier, his body was aching even more than was usual after a transformation. Usually, when he woke up, Tony would have his arm around him and kiss his head when the others weren't looking. But this time, Tony was staring at him from the other side of the quinjet.

"What…what happened?"

No one answered, but Bruce could hear the sound of a news broadcast coming from the cockpit. He turned his head and saw a television screen displaying a video of the Hulk rampaging through downtown Johannesburg. Bruce groaned and put his head in his hands; it was worse than he had imagined. The last thing he remembered before transforming was his head fogging up and the pain of the Hulk forcing his way to dominance.

When they got to Clint's safe house, the first thing Bruce did was ask Mrs. Barton for directions to the bathroom. He stayed in the shower until he had used up all the hot water; he didn't want to have to face everyone after what had happened in Johannesburg.

Bruce put on the sweatshirt and sweatpants he had gotten from the quinjet and stepped into the bedroom. Tony was standing by the edge of the bed, looking uncomfortable.

"There aren't enough beds, so we have to double up."

Bruce pulled out the covers and got into bed. He had been too upset to sleep on the quinjet, so he was still exhausted from the transformation.

"Okay."

Tony shifted his feet and looked at the floor.

"Can I share with you? I didn't know if we were still, still…."

Bruce had completely forgotten about the events of earlier that day, but it explained why Tony hadn't been sitting with him on the plane.

"Fighting? I don't want us to be. I'm sorry I stormed out earlier. I do trust you; I was just angry at myself. I've caused so much destruction already, and now Ultron, and Johannesburg."

Tony sat on the bed next to Bruce.

"Don't be sorry, Bruce. You were right; I messed up and I said a lot of stupid stuff I didn't mean. As for Johannesburg, it wasn't your fault, and it wasn't the Hulk's fault either. It was that girl, she made you do it."

Bruce sighed and shook his head.

"Tell that to everyone who just had their city destroyed, I'm sure it'll make them feel better. It just shows that I'll always be dangerous, no matter how much control I have."

Tony got under the covers next to Bruce.

"That's not true! You help the team, you and the Hulk. And you help me. Look, dealing with everything the happened in New York hasn't been easy for me, but I wouldn't have gotten through it without you. I love you."

Bruce looked at Tony and smiled. He still felt horrible, but having Tony with him made it bearable.

"I love you, too."

"Come here."

Tony held his arms out, and Bruce rolled over so that his head was lying on Tony's chest and his arm was draped across Tony's body. Tony held Bruce with one arm around him and put his other hand in Bruce's hair, lightly pulling on his curls and watching them bounce back.

"Tony, I don't want to keep doing this – being an Avenger. I know that the Hulk isn't all bad, but I just can't do it anymore."

Bruce waited to hear Tony's reaction. Tony was always telling him how helpful the Hulk was and how he didn't need to be ashamed or feel guilty about the destruction he caused. But after years of working with the Avengers, he just wanted to relax."

"Okay."

Bruce picked his head up and looked at Tony.

"Okay?"

Tony smiled at him.

"I know this has been hard for you, and I don't want you to do anything you don't want to do. All I want is for you to be happy. And to stay here with me."

Bruce smiled and put his head back on Tony's chest while snuggling in closer to him.

Clint walked around the kitchen, helping his wife, Laura, get dinner ready. They had pushed a few tables together to accommodate all of their guests.

This had been the only place he could think to go after everything that had gone wrong with Ultron. Clint was getting a bit tired of Stark; this wouldn't have happened if he hadn't messed things up like usual. Laura finished putting out the food and took off her apron.

"Clint, honey, why don't you call everyone for dinner."

"Alright."

He knocked on his kids' doors and then went down the hallway to the guest rooms. Natasha had made herself at home in the room she always used when she stayed with Clint and his family. Steve and Thor were relaxing on their bed, with Steve reading a book and Thor throwing his hammer in the air, looking bored. They were both so heavy that the mattress was sagging under their weight.

Finally, he stopped by the room Tony and Bruce were sharing. The door was closed, but he didn't think anything of it and swung it open. Both of them were fast asleep, with Bruce lying on top of Tony and their arms around each other.

Clint stared at them for a moment before quietly closing the door and walking back to the kitchen. The rest of the team and his family were already sitting at the table, and Natasha turned him.

"Where are Tony and Bruce?"

"Uh, they were asleep. I didn't want to wake them."

When Tony woke up the following day, he reached across the bed for Bruce but only felt cold sheets. Tony's heart rate sped up, and he jumped out of bed, trying to stay calm as he hurried out of the room. He burst into the kitchen, where he saw Steve, Natasha, and Clint sitting at the table.

"Has anyone seen - ?"

Tony stopped short and let out a sigh of relief when he saw Bruce standing in front of the stove flipping pancakes. Laura was handing out sausages to the others, and Tony realized that he was the last one up. Bruce turned around and smiled at him.

"Good morning, Tony. Do you want breakfast?"

He put a pancake on a plate and handed it to Tony, who was still standing in the middle of the kitchen. His heart began to slow down as he sat next to Steve.

As the Avengers ate, Steve lectured about the need to regroup and locate Ultron, but Tony was barely listening.

It had been days since he had unleased Ultron into the world, which should have been enough time for an evil supercomputer to have it in the palm of his robotic hand. However, there were no reports of wayward nuclear weapons brings governments to their knees.

Tony was so deep in his thoughts; he didn't even notice Steve was talking to him until Bruce said his name.

"Tony?"

"Yeah, what? Sorry, I was –"

Steve cut him off and gave him a look that said he was trying to resist the urge to roll his eyes.

"I was just saying that Natasha, Clint, and I are going to Seoul, but first we're going to drop you and Bruce off at the tower."

Tony nodded absentmindedly, but his mind was still racing. Jarvis had disappeared after Ultron's attack, and Tony had thought Ultron had killed him, but maybe that wasn't the case.

Before Bruce got on the quinjet with the other Avengers, Tony pulled him aside.

"Can you go back to the tower by yourself? I'm going to go to Oslo. I, uh, I need to check on something."

Tony thought Bruce would question his vague statement, but instead, he just nodded and got on the plane.

When Bruce returned to the tower, he went straight to the lab and started getting his equipment together. By the time Clint and Natasha returned with Ultron's new body, he was ready to degenerate the synthetic tissue.

Disabling the body would prevent Ultron from "evolving," but Bruce still couldn't get rid of the pit in his stomach. No matter how many of Ultron's physical forms they destroyed, he would still exist through the internet, like an ill-advised tweet that would live on forever.

Just as Bruce was about to begin the process, Tony rushed into the lab and displayed a hologram in front of him. Bruce raised his eyebrows as he looked in disbelief at the orange orb.

"Hello, Dr. Banner."

Tony grinned proudly at Jarvis.

"I found him in Oslo, he was protecting the nuclear codes from Ultron."

"Tony –"

Tony rushed over to Bruce and grabbed his arms. He had a frantic look in his eyes that was even more intense than two days prior when he was convincing Bruce to help him create Ultron.

"I know what you're going to say, and you're right, it's crazy, but if we put Jarvis in this thing, it will be him, not just some alien stone, and –"

Bruce cut Tony off before he could run out of breath.

"I was going to say you're right. At this point we've got no other way to beat Ultron."

Tony was staring at Bruce like he couldn't believe what he had just heard. Truth be told, Bruce could hardly believe he had said it. This had been where it all went wrong, leading to Ultron, their fight, and the Hulk in Johannesburg.

Bruce shook his head and almost laughed at himself as he began setting up the cradle. Doing the same thing twice and expecting different results may be the definition of insanity, but at this point, insanity was their only option.

The synthezoid's matrix was 97% uploaded when Steve and the two enhanced twins busted through the lab door. Bruce had only caught a glimpse of the girl right before she had attacked him in Johannesburg, but the memory of her pulling the Hulk from his well-sealed container in the back of Bruce's subconscious was seared into his mind.

Bruce was frozen still, but Tony continued to type away on the computer and didn't seem fazed when Steve stormed over to him.

"What do you think you're doing?"

Tony didn't even lookup.

"Uh, saving the world?"

Bruce tensed up and took a step towards Steve. It wasn't the first time he had feared that Tony's very human body wouldn't be a match for Steve, but he had thought Tony and Steve had resolved their differences long ago.

"Steve, I know this looks insane, but –"

Clint had rejoined them, and he rounded on Bruce, eyes piercing into him.

"Really, Banner, you're agreeing with him again? I thought you would have learned your lesson by now."

Bruce was taken aback by the sudden reproach. He knew he should be grateful that Tony had been taking much of the condemnation for creating Ultron when he was equally at fault, but he wasn't used to confrontations like this.

Before Bruce could respond, the girl spoke up in a thick Sokovian accent.

"I told you Stark couldn't help himself. The only thing he knows how to do is destroy."

Bruce felt his anger boil up in a way that it hadn't in years. Even when Tony had snapped at him, he only felt sad and upset. But the vitriol the team, and now a Hydra agent, had been spewing at Tony was too much for him to bear.

"What is she doing here?"

Steve ignored him and slammed the laptop's lid down, so it almost hit Tony's fingers. Then he walked over to the cradle and pointed his shield at it.

"You two need to shut that thing down, now!"

Tony opened the computer back up and glared at Steve.

"You and the Grady Twins need to shut up and let us work."

But when Tony looked back down to continue the upload, Steve slammed his shield into the cradle. The glass cracked open, exposing the synthetic body inside. Tony quickly summoned his armor, but in the commotion, the fast twin had zipped around the room and unplugged all the wires connecting the cradle to the computer.

Steve was aiming his shield at the body, ready to deliver the final blow, when Thor burst into the room. Wordlessly, he swung Mjolnir above his head and summoned a bolt of lightning from the night sky, and directed it towards the cradle. Bruce ducked out of the way, and he tried to look for Tony, but the sparks flying off the cradle were blinding him.

When they had dissipated, he raised his head and saw the synthezoid lifting itself out of the cradle. He had purple skin and the orange gem from Loki's scepter embedded in his forehead. He looked at his reflection for a moment before forming a grey suit and cape over his body.

Finally, Tony broke the silence.

"Jarvis?"

The synthezoid looked at Tony, but he showed no signs of recognition.

"I am not Jarvis."

The voice sounded like Jarvis, but Bruce could see the disappointment in Tony's face at the correction. He had already believed he had lost Jarvis once.

Steve looked suspiciously at the creature in front of them.

"You're Ultron?"

"No, I'm not. I am…"

He trailed off, and most of the Avengers were too shocked to say anything, but Thor approached him, leaving Mjolnir on a table in a sign of good faith.

"Whatever you are, you have been a vision in my head ever since I was attacked by the witch. The mind stone you possess is what holds the key to defeating Ultron."

Thor seemed convinced, but Clint glared at Vision.

"How do we know that's true, and you're not just another one of Stark's genocidal robots?"

Vision did not seem offended by the accusation, and if Bruce could detect any emotion from him, it would be sorrow.

"I don't have a way to make you trust me, but I am your only chance at defeating Ultron."

As he finished, Vision casually lifted Mjolnir off the table and handed it to Thor. Thor stared wide-eyed at Vision before accepting his hammer and turning back to the Avengers.

"The time has come."

Clint and Natasha had located Ultron, so soon, the Avengers were on the quinjet flying to Sokovia for the second time that week. As they approached the drop point, Bruce sat in the back, whispering to Tony. They had decided that he would stay on the quinjet during the mission and communicate with Tony via headset.

Tony had been uncharacteristically quiet since the incident in the lab, and Bruce thought he knew what was bothering him.

"Tony, I know you hoped you could transfer Jarvis's consciousness into Vision. It can't have been easy for you."

Tony sighed and smiled sadly at Bruce.

"I did, but I talked to him about it after I found him in Oslo. He wanted to do anything he could to defeat Ultron."

After a couple moments of silence, Tony grinned, and Bruce could see that it was genuine this time.

"You know, Vision is basically our son."

Bruce laughed, but he couldn't help his heart fill up at that.

"Then Ultron is our son, too."

"Well, the first one's always the hardest."

The quinjet landed in a clearing near the forests in the outskirts of Sokovia's capital city, and the Avengers disembarked, all suited up for battle. Bruce grabbed Tony's arm before he got out and pulled him close.

"Tony, if things are going badly, if you need the Hulk –"

Tony held his hand up to stop him.

"We won't, I promise. And if we do, I promise I'll tell you."

Bruce nodded and squeezed Tony's hand. He always worried about Tony when they went on missions, but at least he had known the Hulk would protect him. This time, he wouldn't be there.

"Be careful."

Tony looked out of the jet to make sure none of their teammates were watching them, then turned back to Bruce and gave him a kiss.

"I will."

The minutes turned into hours, and Bruce was still waiting anxiously on the quinjet. He could hardly see what was going on in the city, but he occasionally saw a bolt of lightning shoot out of the sky. Tony hadn't called him yet, and while Bruce was happy that there was no need for the Hulk, he had to resist the urge to call Tony and ask if he was okay.

Just as Bruce was beginning to think he couldn't take the stress any longer, he felt the ground begin to shake beneath him. Initially, it felt like a small earthquake, but it intensified until Bruce was grabbing onto his chair to keep himself from falling. He struggled to stand, and when he looked out the window, he saw the trees at the edge of the clearing disappear, as if they were falling off a cliff.

Moments later, he heard the roaring sound of an engine and saw the helicarrier rise up from where the trees had fallen. Bruce ran out of the quinjet towards the helicarrier, and as he crossed the drawbridge connecting it to the clearing, he could see Coulson standing on the deck.

"Dr. Banner, glad to have you aboard."

Bruce tried to catch his breath once he was safe on the helicarrier.

"What's going on?"

"Ultron has lifted the entire goddamn city into the air."

Bruce whipped around, and for the first time in his life, he was glad to see Nick Fury walking towards him. Fury and Coulson ushered him inside, but he looked out the window and saw that they were thousands of feet above Earth.

He was staring wide-eyed at the floating city when he heard Tony's voice in his ears.

"Bruce, are you there?"

"Yes, I'm here! Are you okay?"

Tony's voice brought him back to his senses, but all he could feel was fear. Ultron was holding millions of civilians, and his teammates, hostage.

"Yes, but Ultron is trying to get to the core. I need to get in there and blow it up."

He paused, and when he continued, Bruce could hear his force was shaking.

"Bruce, I, I might not –"

Soon it dawned on Bruce that this wasn't a call for the Hulk; it was for something much worse. But his minding was racing, and he cut Tony off.

"Wait, get me a reading of the vibranium in the core."

Bruce looked back up at Fury, who was directing lifeboats to evacuate people from the city.

"This is the same helicarrier we were on in New York, right? Do you still have the lab?"

Fury looked at Bruce oddly but didn't question him as he led him to the lab. It had obviously been repaired since the last time Bruce had been there, but all the equipment was in the same place. Unfortunately, Bruce didn't have time for nostalgia as he started up the computers and spoke frantically to Tony through the headset.

"I can reprogram your gauntlet to shoot enough gamma radiation at the core. It will have enough force so you can take it off and get out before it explodes."

Tony connected his suit to the lab computers so that Bruce was able to access the code. Programming wasn't his specialty, but he had learned enough about how the Iron Man suit worked from his time helping Tony design the Hulkbuster. He reprogrammed the repulsers to shoot gamma radiation and transferred almost all the power from the arc reactor to one of the gauntlets.

After several nerve-wracking minutes, he connected to Tony again.

"It's ready now. Leave your gauntlet on the core and get as far away as you can."

"Okay, I will. But if it doesn't work –"

"It will, Tony, I'm sure of it."

His brain was not at all sure it would work, but his heart knew it had to.

"I love you, Bruce."

Bruce could feel tears streaming down his face, but he tried to hold himself together long enough for his pain to not show in his voice.

"I love you, too."

The line closed, and Bruce sank to the floor. He was sitting in the same spot that Tony had poked him all those years ago. After a couple minutes, the sound of a loud explosion echoed through the helicarrier. The entire room shook, and Bruce had to dodge a monitor that almost fell on his head. He ran out on the deck to see that the whole city had been blown apart, its pieces raining down on the country below. Bruce stared in horror at the sight before him. Most of the people had been evacuated onto the helicarrier, but some hadn't made it in time.

Bruce breathed a sigh of relief when he saw Clint sitting in a lifeboat with a group of unaccompanied children. Steve and Natasha were talking in hushed voices to Fury on the deck, and Thor was flying around the helicarrier, fending off pieces of rock that were falling dangerously close to the refugees.

Bruce looked desperately out at what remained of the city until finally, he saw what he was looking for. Tony flew out of the rubble and landed on the deck of the helicarrier, like something out of a fairytale. Bruce almost cried with joy as he vowed to himself never to let Tony out of his sight again.

Bruce and Tony were walking through the nearly completed New Avengers facility, and Tony was showing Bruce something on his tablet. It had only been three weeks since the Ultron Offensive in Sokovia, but Tony had already managed to refurbish an old Stark Industries warehouse in upstate New York.

"Your room is right next to mine and Rhodey's is on the other side, and then Thor is next to the kitchen in case he gets hungry. I'm thinking about putting Vision and Wanda near each other because they seemed to hit it off, but I'm not sure we want our son dating an ex-Hydra agent just yet."

Bruce grinned at Tony. The two of them had decided to retire as active-duty Avengers; their new roles would be technical and scientific experts for the team and, in Tony's case, bankroller.

When they got to the back of the lobby, Bruce pulled Tony into a deserted hallway so quickly he almost dropped his tablet.

"Mmmm Dr. Banner, I'm starting to think you don't care about my floor plans."

"You're the only thing I care about."

Tony let the tablet fall to the floor as he wrapped his arms around Bruce and pulled him in for a kiss.

Thor stepped out of the New Avengers facility, lost in thought. He had come into contact with first the Tesseract, then the Aether, and now the Mind Stone. Additionally, he had gotten word from Asgard that the Power Stone had been detected recently.

Even though Thor considered himself too mighty to be affected by Midgardian forces, the visions he had had were too concerning to be ignored. Now that his friends' homeworld was safe from the forces of evil, it was time for him to go on his own quest.

Thor had stayed just long enough to bid farewell to his teammates, but he hadn't gotten the chance to say goodbye to Stark and Banner. He had been looking for them in the facility when he saw them kissing in a hallway.

Thor had elected not to disturb them; he knew how much he valued his time with his own love, Jane. He had stayed with her on Midgard for two years, but now he was going to leave her was again for gods know how long.

He would have to invite Stark and Banner to join them on a "double date," as Jane called it. They had partaken on many such dates with their friend Darcy and various men, but Thor had never been impressed by them. However, Jane always spoke of how she admired his two teammates' scientific achievements.

Thor pushed Jane out of his mind and prepared to call Heimdall; he had much more pressing matters to attend to.