<Sorry this took such a long time to post, I didn't have a lot of inspiration for a while and I also didn't have time. This one's definitely not one of my better ones, but I still felt like I should finish the story.>

"What the hell happened? And who the hell is she?" Tony practically screamed at Bruce the second he came in the door.

"They both just...fainted all of the sudden." Bruce still sounded dazed.

"Why were you with them? Who is this? Bruce? I need answers!" Tony took his friend by the shoulders and shook him. Bruce shook his head and his eyes seemed to clear.

"This is Payton. She's Peter's... friend. I think she might be a mutant too."

Tony just looked at him in astonishment. Bruce was not answering any of his questions, he was only creating new ones. He looked at his friend closely, noting the hesitant words and the slow movements. "Are you... being mind controlled?"

"Maybe?" Bruce asked, sounding for just a second like himself. "But it doesn't matter. People are sick. I need to help them. I need to help Peter."

Tony seemed to remember the graveness of the situation then, as he viewed the two teens on the bed. They look so much alike, he thought, but then he scoffed at that idea, chalking it up
to the weird lighting in the Medbay. Obviously Peter couldn't be related to this girl in any way.

"I'm going to run some blood tests and see what's going on. Tony, you need to leave the room. There could be potentially toxic chemicals in their blood, and I don't want you exposed."

Tony didn't move. "Bruce, I literally had palladium poisoning, I think I can handle some spider-bite mutations."

Bruce knew better than to try to fight Tony's stubbornness. "Fine, but suit up." He gestured to a containment suit hanging on the wall.

Bruce ran through several tests, drawing blood from the two unconscious teens and analyzing the blood. He sent the results to Friday, and it beeped as it finished. "Would you like me to read the results?" The AI asked.

"Yeah, sure." Bruce nodded mindlessly, but even as he did that, he felt like it was the wrong decision. "Actually, never mind..." but FRIDAY had already started, so Bruce trailed off.

"Both Peter and his biological sister appear to be suffering from delayed muscular and bone pains. Their bones are beginning to hollow out, making their body composition similar to that of a spider, which has no bones. Their blood is mutating rapidly, changing into a venomous secretion. Payton is further along than Peter, as her body is not as highly trained, and her healing factor is less than Peter's. Without treatment, she will likely last less than a week, and Peter has maybe a week beyond that."

Bruce tried to keep a handle on the situation, "what would you suggest is te best course of treatment—" He cut off rapidly as he heard a thump behind him. He turned to see Tony unconscious on the floor. "Oh, shit!"

The doctor ran to Tony's side and checked his pulse. "Tony? Tony wake up!" Sighing, Bruce told FRIDAY to alert Steve. When the Captain arrived, Bruce explained what happened. "Tony found out some surprising information, and he passed out from the stress. Can you help me carry him to a bed? He'll be fine in a little while, this has happened before. I need to take care of Peter and Payton."

"Peter and...?" Steve looked over at the two kids in the bed. "She's his sister?"

Bruce looked surprised that he had figured it out so quickly. "Yeah, and she's superhuman too. They're also both apparently..." he couldn't finish the sentence.

Steve understood and gently put his hand on Bruce's shoulder. "Well if they have you taking care of them, I'm sure they'll be fine."

"Thanks Steve." Bruce said softly, and the. He turned his attention back to FRIDAY and his patients.

"FRIDAY, what is the best course of treatment?"

"They will need an immediate blood transfusion. They both have B positive blood, and I have already contacted Bucky and Natasha, who both also have this blood type. Once the toxic blood has been flushed from their body, they will need repeated supplement injections to begin reversing the mutations in their DNA. Dr. Cho and Dr. Amsterdam, Shield's head medic, will be here shortly to assist."

At that moment, both Bucky and Natasha came running into the Medbay, with Sam and Wanda close behind. Bruce explained the situation to them quietly, and both Natasha and Buck quickly agreed to help. "We love Peter, and we'd do anything to help him, and if this is his sister, and a superhuman at that, we're going to help her too," Natasha eloquently put it.

Bruce nodded with appreciation. He prepped them both for the procedure and began the first step of saving Peter and Payton.

Thankfully, the transfusion worked, and their blood toxicity levels began to decrease. Bruce worked tirelessly in the lab, making the necessary drugs and taking care of the kids. Days passed without him realizing, and he only slept when one of the other avengers forced him to leave the lab, at which point he would basically collapse into a state of hibernation, and then wake up ready to do it all over again. Every day that passed and the kids didn't wake up made him lose more hope. But he couldn't give up. He had to save Peter. He remembered back after the Sokovia accords, when the team had almost fractured for good. Peter was one of the only reasons they were all okay with each other now. He had helped them all heal emotionally as much as Bruce physically helped Peter heal. He could not fail this kid.

Bruce readied another dose of the healing agent and slipped it into their IV's. Methodically, he went through the process of checking their vitals, knowing nothing had changed.

But something had changed. Both of their heart rates were increasing, as was brain function. Bruce's breath caught. Their stats were almost... normal. I have to tell Tony, he thought, but then he changed his mind. If it wasn't... he couldn't do that to the man. He would bide his time until he knew for sure. But when he turned back, he saw two pairs of matching blue eyes staring up at him. He rushed over. "You're awake." Bruce said incredulously. Peter just nodded. He couldn't speak, because Bruce had been forced to intubate them since the IV wasn't providing enough nutrients. He couldn't believe they were actually awake. He patted Peter's hand, and called Tony.

It took several weeks for them to make a full recovery, but eventually they were both up and walking again. Bruce had figured out how to selectively edit their DNA so they wouldn't have these problems again. Life slowly adjusted. Payton would come to the tower on some weekends, and she began fighting crime with Peter. They were careful to keep her identity completely hidden, but there was still the fear that someone would find her. However, they knew that no matter what happened, they would be strong. Payton had mental willpower of steel. After all, she basically had kept both of them alive by her pure belief that Bruce would save them. He had succeeded, and now their lives were completely changed.

As soon as they woke up, the first thing Tony did was take his Spider-kid and his newly basically adopted daughter to a Broadway show. He even let them sing along to every single word of The Lion King. If that's what it took to make his kids happy, then he would do anything.