A/N: I love Bruce. He's so much fun to write.

OOOOOOOOO

It took a while to tell the story, but by the time Stark was finished Bruce was looking both amazed and confused. Amazed because Tony really did sound like he was settling (settled?) down, and confused because he didn't understand what the man was telling him about the boy's abilities.

"What do you mean when you say that he can stick to walls?" he finally asked. "Is that a metaphor for something?"

Steve smiled at that.

"No. He sticks to walls."

"What?"

"I can pick Peter up and press him against a wall and he won't fall," Tony said, also amused at the question – although understanding, completely, why it was confusing. "He sticks."

"How?"

"Same way that he can lift a ton," Steve said. "Whatever bit him, it gave him some seriously interesting abilities."

"So… some kind of mutation?" Bruce asked. "Or-"

"JARVIS thinks it was a wolf spider," Tony said. "Peter's DNA is riddled with a matching DNA. He can stick to walls, he's stronger than pretty much anyone but Steve – and maybe your green alter-ego, of course – and he's a durable little guy."

"And he can see in the dark," Steve added.

"Not complete darkness," Tony corrected. "At least, I don't think so. I haven't really tested it."

"He can really stick to walls?"

"He can. Someday, with some practice, he might be able to climb them, as well. He's not very good at it, just yet."

"I had to rescue him from the gym wall a while back," Steve said.

"And I've pulled him off the shower wall, when he wanted to experiment on himself and see if soapy walls made any difference."

"Did they?"

"Nope. He just hung out until I rescued him. Just like when Steve did it in the gym."

"Can I see it?"

"We're not going to let him climb back up the gym wall," Tony said. "It was too high, and-"

"Not on the gym wall," Bruce interrupted. "Just on any wall. Or can he stick to anything? Have you tested him?"

The scientist in Banner was already itching to do experiments.

"He's outside playing on the playset that Steve put together for him," Tony said. "If you want, we can go watch him. He's bound to end up showing you what he can do without even realizing that you're analyzing him. Or you can just look at some of the recordings that JARVIS and SHIELD have made."

"Can I do both?"

"Sure."

Banner got to his feet, already reaching for the jacket he had draped over his chair.

"Let's go."

Tony would have liked another cup of coffee, but he could understand Bruce's desire to see for himself what Peter was capable of – and Tony really couldn't wait to see his friend's reaction. He shrugged and got up, as well, looking at Steve.

"Are you coming?"

Rogers shrugged, too, affecting a nonchalance that he didn't feel. He was looking forward to Banner's reaction to Peter, as well.

"I'm certainly not going to sit in here, by myself. The kitchen people might try to recruit me to do dishes, or something."

"Or worse, help with dinner," Tony added.

"Exactly."

The three men headed for the door.

OOOOOOOO

"Well, that's something you don't see every day…"

"Right?"

They were standing on the back patio area of the compound, just at the fringe of the grassy area that the playset had been built. Tony had gone over to join Peter, Clint, and Sam. Peter was the only one actually playing on the crossbeams and bars, swinging from them happily. The adults were engaging with him, gently teasing him, and sometimes swinging him – either in a swing, or sometimes just from whatever bar he happened to be holding onto at the moment.

Bruce watched in amazement as Tony turned the boy upside down in his arms, then hung him by his feet to the cross beam that supported the monkey bars. When he let go, Peter had simply giggled – and stayed where he was, as if there were giant magnets on the soles of his boots and the beam was made of metal rather than wood.

"How long can he hang there?"

"No clue."

"What if he fell asleep?" Bruce asked. "Would he still stay there? Or would he fall?"

Steve shrugged.

"We haven't done a lot of experimenting on that kind of thing. Tony might know – maybe they've done some at home. He seems to be able to hang – or stick – until he lets go."

"But he got stuck on the gym wall."

"He was pretty high up, by then. Natasha thinks that he was afraid to let go – or afraid of how high up he was – and whatever keeps him sticky wouldn't release him because he didn't want to fall."

"The same would apply to when he was stuck in the shower," Bruce decided, walking over to Peter. "If he didn't know how far up he was, or couldn't find a safe way to land."

Tony heard this last part as Banner walked over, and knew what he was talking about.

"That would be my guess, as well," he agreed. "Peter? Bruce is interested in how you stick."

The boy's face was turning red from being upside down, but he smiled, cheerfully.

"I just do."

"I see that. It doesn't hurt?" Banner asked, coming to stand under him, and reaching out to touch him.

"No."

"Can you let go?"

"I'm not supposed to drop, anymore," Peter told him. "Natasha doesn't like it."

"He almost landed on his head," Sam said.

"Go ahead, buddy," Tony said to him, reaching up. "I'll catch you."

A moment later, Peter was 'falling' into Tony's arms, and the billionaire swept him upside right, making him giggle. Which made Bruce and the others smile in response.

"So he has an interesting skillset, and he's intelligent to boot," Bruce said, turning his attention to the little boy. "Are you going to be an Avenger?"

"Yeah. Maybe. Or Batman…"

Tony rolled his eyes, ignoring Sam's snort of amusement.

"The Batman gig is already taken, buddy." He hugged his son and then set him down. "Let's go inside, alright? You're cold and I'm hungry."

"Okay."

OOOOOOOO

As they had dinner, Peter interrogated Bruce. Now that he was more comfortable with the man – and Tony was pleased to see that the little boy was comfortable with him, so his stomach clearly wasn't warning him to stay away – Peter was excited when he found out that Bruce was a scientist. He asked him about his experiments, and what he'd been experimenting on, and where he'd been and what he'd been doing and learning while he'd been gone.

Tony was amused that it was Bruce who was a little uncomfortable. Bruce was something of a loner – he had to be, really, because he isolated himself from people for fear of losing control of the Hulk and hurting someone. Peter was an animated little guy with people that he liked and not afraid of conversation. By the time they were finished eating – and Peter had negotiated for hot fudge on his ice cream – Peter had made himself a new friend, and Bruce had found himself charmed by the little boy.

"How long are you going to be in town?" Stark asked his friend, watching as Peter climbed into Natasha's lap to cuddle.

Bruce smiled when he noticed the same thing, and Romanoff smirked, not at all chagrined at being caught being used as a cuddle buddy for the little guy.

"Probably through the week. I have a few things I want to work on, here, and an experiment that I'll work on in the lab at the tower – unless you've given away my things and rented out the lab?"

Tony snorted.

"I thought about it, but no."

"You're going to be here all weekend?"

"Tonight and tomorrow," was the reply. "We're going home, tomorrow evening. I'm going to try out the new suit and see how it does, and give the Avengers a chance to hang out with Peter, for a while."

The boy smiled, nestling closer to Natasha, who brushed a kiss against his cheek.

"Good thing," she said. "We made plans for him for tomorrow morning."

"You did?" Peter asked, looking up, excitedly. "What?"

"Secret things," she said, mysteriously. "But you need to make sure you don't stay up too late, because we're getting up really early."

"All of us?"

"Yes."

Peter looked at Tony.

"Even you?"

"No. This is an Avenger/Peter thing. No dads allowed."

"Oh."

Tony smiled.

"They'll have you in the morning until after lunch. After lunch, you can watch me try out the new suit."

He needed the morning to finish the final configurations, and while he didn't necessarily think Peter would be bored, it wasn't as interesting as what Natasha and the others had planned. The boy didn't know it, but they were going to be taking an early morning flight on the Quinjet out to Clint's farm. They'd spend the morning sledding with Clint's kids. None of the hills at Barton's were so steep that Tony was worried, and he – of course – trusted the Avengers with Peter's safety. Peter would have lunch at Clint's with the others, but then it was back to the compound to watch Tony test the new suit – providing that Tony's morning was productive.

The billionaire was looking forward to the next afternoon. Not because of his new suit, though, but because of the new one that had been made for Peter. One that was going to be a total surprise, apparently, even though Tony had told him that he'd make him one. Peter either forgot, or hadn't thought that Tony was serious. He was still learning, of course, but this surprise was going to be great as far as Tony was concerned.

Peter looked excited, but even Tony wasn't sure which part was more exciting to the boy. Spending the morning with the Avengers, or watching the newest Ironman suit be tested.

"Wow."

Tony looked at Bruce.

"Did you have any plans for this evening?"

"Catching up with you and the others."

"Good. Since you're the guest, more or less, you can decide the evening's activities."

Banner smiled, uncertainly. His experience with children ranked right up there with his experience with mountain lions.

"What are my options?"

"We can play Legos," Sam said.

"Or we can go to the gym and play in the ball pit," Steve told him.

"Or…" Natasha said, running her fingers idly though Peter's curls. "We can build hot wheels racetracks and see how intricate they can get only using gravity and inertia."

Stark snorted.

"You're so hot when you say nerdy things like that, Romanoff."

She smiled.

"Watch out, Stark. I'll tell Pepper that you're flirting."

Peter giggled, and turned in Natasha's lap so he could look at Banner.

"What do you want to do, Bruce?"

He, of course, was happy to do any of those things.

Had anyone told him that this was going to be what he was going to be doing that evening, the newcomer would have made a derisive sound and waved them away. But sure enough, they were all watching him – Peter more expectantly than anyone, he decided.

"I always did like Hot Wheels when I was growing up," he admitted. He smiled when Peter cheered. "Do we have enough track pieces and cars for everyone to play?"

He wondered if Captain America really was going to build a racetrack with an eight-year-old. Never mind Tony Stark – he had to since it was his boy, but Steve and Natasha? This he had to see, really.

"Of course, we do," Sam assured him. "Seems like every time one of us is anywhere near a toy store – or the internet – we're always ordering more." He slapped the table, cheerfully, and scooped Peter out of Natasha's lap before she could resist. "Come on, kid. Let's go get the racetrack stuff and bring it in here."

"Okay."