AN: Writing what Sirius was up to turned out harder than I thought, so, this chapter is showing what he did in October with a brief mention of what all he did after leaving Hogwarts, I just couldn't get that part written well enough, hope you enjoy anyway, and there are a couple of times skips, and show why Sirius hasn't shown back up in the wizarding world yet, and why he wasn't there when Harry's name came out of the goblet.

Disclaimer:I don't own HP or Marvel, this is done just for fun.

Chapter 24: New York.

October 4, 2013

Sirius sat in his hotel room, legs propped up on the desk in front of him, cheeseburger in one hand, his omnioculars held to his face with the other; he was watching Avengers Towers, which was across the street. He and Remus Lupin had arrived in New York around five yesterday morning, and the first thing they did was check into a hotel. While Remus went back to bed, Sirius stayed up. After Remus fell asleep, he left the hotel, went to the county clerk's office, broke into the building from a side door, while wearing the invisibility cloak, stole the blueprints to Avengers Towers, then on his way back to the hotel, took a close-up look at Avengers Towers and when he returned to the hotel room Remus was still asleep.

He finally woke up at around one in the afternoon, and then Sirius left him in the hotel again to get them something to eat. While he was out, he went ahead and bought him and Remus both a cell phone; since he gave Andromeda the second mirror, they would need them to communicate. They spent a whole day trying to figure out how to use them. It has been three days since they arrived in New York. Sirius had just returned to the hotel from going out and getting them some lunch about five minutes ago. Remus was in the shower, so Sirius sat back at the table, got out his food, and started eating while continuing his spying on the muggle superheroes across the street, which ended up being boring. They were in and out a lot, but while in the tower, Stark and Banner spent a lot of time in their labs. Clint Barton was hardly ever there, same with Natasha Romanoff, Steve Rogers, and some good-looking bloke with a metal arm spent a lot of time working out in the gym.

Sirius had the blueprints spared out on the table, and he sat the omnioculars down next to it and took a bite of his burger. When he had left Hogwarts, he went straight to his vault at Gringotts, drew out a few thousand galleons, then exchanged that for muggle money. Once Sirius left the wizard bank, he went to a muggle one wanting to exchange some of the British muggle currency for American currency, but the teller told him it would take a few weeks to come in, so Sirius had to put his visit to the States on hold for a couple of weeks, while Sirius waited, he went back to Loki's cottage, and went through some of those Dark Arts books he brought home from Grimmauld Place but didn't find anything that would help him figure out how Voldemort survived the killing curse, so he went to a muggle library and checked out some books on the Avengers or at least the ones that had books about them, which was just Steve Rogers, and Tony Stark. During his time reading, Sirius heard that S.H.E.I.L.D. had their helicarrier docked off the coast of Ireland, so Sirius grabbed the invisibility cloak and went to check it out, he searched that whole ship but unfortunately didn't discover anything useful, so, he headed to Remus's cabin a day before the full moon so that he could be with Remus during it, and to give him the ten-month supply of Wolfsbane Potion, Sirius had gotten Loki to make along with a supply of that special tea that helped Remus recover quicker, and though it did help it didn't work as well as it did when Loki made it, Sirius figured he must have done something wrong. However, he didn't know what; he made it the way Loki showed him. A week after the full moon, Sirius returned to the muggle bank to pick up his money and the following day he and Remus apparated to New York.

It was in one of Steve Rogers's books he found a connection between that weird symbol the world cup attackers wore and a group called Hydra that Steve Rogers fought against and their leader Red Skull; Sirius had first thought the Avengers might know who the siblings that were after Harry was, due to thinking, they bound to keep track of super-powered people like that. Now he was sure they knew because that symbol meant those wizards, for some reason, had joined the modern-day Hydra. According to the muggle newspapers, Loki used to buy to keep track of what the Avengers were doing, they kept all of Hydra's old files, and Sirius hoped they were in Avengers Tower.

Sirius heard the shower shut off, and five minutes later, Remus walked out of the bathroom in blue jeans and pulling a t-shirt on over his head. For a split second, the scar on his side from when Greybeck attacked him could be seen before he coverd up the bite mark pulling the shirt down over it. Sirius set the burger on its wrapper he had spread out on the table, then picked up the bag of food and pulled out a burger.

"Hungry, Moony?" Sirius asked, tossing the burger at him. Remus caught it with one hand.

"Thanks," Remus said, unwrapping the burger.

"That's from a place famous among the muggles, I wanted to try it since it's so popular." Sirius said, "But to be honest, I find it overrated, not as good as you would think it would be; the chips are good, though, but unfortunately, their ice cream machine was broken."

"I still can't believe you were able to apparate yourself, me, and our staff to New York," Remus said, walking over to the balcony to look out, "It takes an extraordinary amount of magic to apparate that far." Sirius pulled an order of large chips out of the bag and walked over to Remus.

"Yeah, well, Reigny's scepter didn't only give me mind abilities but also boosted my magic a bit." Sirius shrugged, holding the chips out to Remus; he took one.

"Have you seen any of them today?" Remus asked, taking a bit of his burger.

"Just Iron Man, the git," Sirius answered, sticking a chip in his mouth.

"I can't believe I let you talk me into coming with you," Remus said. "I don't think this is a good idea."

"We'll be fine; stop worrying," Sirius said as Remus took another chip. "You'll give yourself grey hair."

"Padfoot," Remus warned. Sirius grinned.

"Seriously, Moony, we'll be fine. I didn't get caught sneaking into S.H.E.I.L.D's helicarrier. I won't get caught in Avengers Tower. I'll be in and out before they know I'm there," Sirius said.

"I'm sorry you did what?" Remus asked, turning to Sirius.

"You don't think I just sat around doing nothing the few weeks Reigny and Harry have been back at Hogwarts, do you?" Sirius demanded, "On top of a lot of other things, I searched one of their ships while under the invisibility cloak."

"Sirius, I can't believe you," Remus said. "No, actually, I can believe you'd be so stupid."

"Relax, I didn't get caught. No one even knows I was there." Sirius said, "Though from what I've overheard, some agents now believe their ship is haunted by some bloke name Coulson."

Remus groaned and flopped down in a chair sitting in the corner, then took another bite of his burger. Sirius turned back to the balcony and finished the chips while Remus finished off his burger.

"Why are you so sure they know who those siblings are?" Remus asked.

"Reigny said that symbol on their robes was familiar but couldn't place where she had seen it, which got me thinking." Sirius walked over to the table and picked up a book about Captain America, turned to the page he had marked, walked over, and held the book out to Remus, who took it and looked.

"Whose Hydra?" Remus asked.

"A group Steve Rogers's fought against during a muggle war, I swear, Moony, they sound like muggle Death Eaters, and their leader was this wacko called Red Skull; he's a muggle Voldemort," Sirius said, "Even favors him, look."

Sirius flipped a few pages back and pointed at a picture of a dark hair and dark eye man.

"He does," Remus agreed, "Well, looks like what Voldemort did before he became all snake-looking."

"Just older." Sirius said, "And look, Red Skull even somehow disfigured himself too." He turned the page and showed Remus a picture that told him why the man was called Red Skull.

"Johann Schmidt," Remus read the name out loud. "Schmidt, that's the name of Durmstrang's new Headmistress." He paused in thought, then shook his head. "Probably just a coincidence."

"Probably," Sirius said, "but those wizards that attacked the campsite were with those siblings that were after Harry, Hydra didn't end with the death of Johann Schmidt. It continued in secret up until the Avengers supposedly put a stop to it last year, but I don't think it ended completely, considering their modern-day leader escaped. The ones who attacked the world cup were wearing their symbol, which means they were Hydra, and if they were part of Hydra, those siblings were too, and if anyone knew who the members of Hydra were and where to find them, it is the Avengers. They kept all of Hydra's old files."

"Sirius, couldn't you just go ask to speak to Rogers and explain the situation? He fought Hydra twice now, and he might be willing to help, at least tell you the name of the siblings, if they know it." Remus said.

"I'm not asking those arseholes anything," Sirius said, "I'm going to sneak in and look into their files like I did on their ship. I wish not to have to communicate with any of them."

"Sirius, the Avengers aren't the bad guys," Remus said. Sirius opened his mouth angrily, but Remus held up his hand. "You hate them because they fought Loki, I understand that, but Padfoot, Loki was the bad guy in that fight."

"Reigny wasn't in his right mind." Sirius defended, "He.."

"He still killed innocent people. Look, I'm not trying to make Loki look bad or anything. I'm just trying to point out that if you went to the Avengers and asked for help, they might be willing, especially since, if you're right, it's a child Hydra is after."

"If I go to them, I risk Reigny getting dragged off to Asgard," Sirius said, "And yes, I know Harry is more important, but what if they decide to lock me up for hiding him or you? What will happen to Harry then? When the people most willing to keep him safe are unable to."

"I get what you're saying," Remus said, "But I can't help but think this is a bad idea. The Avengers aren't the kind of people you want to make mad."

"Have a little faith in me, Moony." Sirius said, "I'll make a plan. I won't get caught. I'll have you helping after all."

"I swear, Padfoot, if you get us killed, I'm going to murder you," Remus said.

"How? You'll be dead." Sirius said, grinning, Remus threw the burger wrapper at him, and it struck Sirius's head and bounced off onto the floor. Remus grinned at Sirius's scowl.

"Do you have any more chips?" Remus asked. Sirius pulled another large order out of the bag and walked over, and handed them to him.

"Thanks, Padfoot." Remus said, "And you're right, the food isn't as good as you'd think, but was still good."

October 24, 2013

"Okay, go over this plan of yours again," Remus said as he walked back and forth in their hotel room. "How do you expect to gain entry inside what is probably one of the most high-tech security buildings in the world?"

"As Padfoot," Sirius answered. "I will act like a stray that wandered into the building, go into the stairway, turn back into my handsome self, get under James's cloak, and you look at the blueprints, and message me where to go from your phone, and use my omnioculars to keep an eye at where everyone is in the building, at least from the side we can see, and alert me if any of the Avengers are out of your sight.

"Why the stairs?" Remus asked, "Why not use the elevator?"

"They might get suspicious if it keeps randomly going to different floors." Sirius answered.

"And how is it that after being here for three weeks, this is the best plan we could come up with?" Remus asked.

"We both decided we didn't know shit about muggle technology, and the amount of magic it would take to fuck with their security system would get the attention of MACUSA, and we don't need those bastards breathing down our necks," Sirius answered.

"Sirius, language, honestly," Remus said, "When are you doing this?"

"Tomorrow," Sirius answered. The eighteenth had been another full moon, and Remus and Sirius had found an old abandoned building a few blocks away, and Remus took some Wolfsbane and curled up as a harmless wolf until the sun rose the following day.

"And there is no way I can talk you out of this," Remus asked.

"Nope, nothing," Sirius said.

"Sirius,"

"Harry is my son, Remus," Sirius said, "I have to do what I can to protect him. I already have to worry about Voldemort returning, and I don't need to add two more powerful people to that list."

October 25, 2013

Sirius got up feeling a little nervous as he showered, then dressed, wearing black jeans and a dark blue dress shirt. He decided to skip breakfast and only have coffee. While he drank it, he went over the plan one more time, then slipped his leather jacket on, put his phone in the inside pocket, folded up the invisibility cloak, and stuck in the samd pocket. Sirius had an Undetectable Extension Charm on it so that he could fit anything in it. Sirius then got in his bag and pulled out an old dagger that had once belonged to his Uncle Alphard, and he found it in the family vault. It was silver with the family crest and motto on the handle, he planned to remove that at some point, but right now, it would do, as he hooked it to his side. Then told Remus to wish him luck, and left the room, got on the elevator, went to the ground floor, then walked out of the building, walked up the street, then went into an ally, shifted into Padfoot, then left and followed the crowd of people to a crosswalk and walked across the road.

As a dog, Sirius walked down the street while having to avoid being stepped on until Sirius arrived at Avengers towers, and went right up to the two large glass doors leading into the building and stood there looking in until someone walked out, allowing Sirius to run in, the lobby was empty except for the woman who worked behind the counter, and she was too busy playing on a phone to notice the giant black dog that just walked passed her desk, and jump up, open the door to the stairway, went in and turned back into a human, Sirius then pulled the invisibility cloak out of his pocket, and threw it over himself, quickly, then pulled out his phone and texted Remus.

"I'm in. Where should I go first?"

"There is supposed to be a large storage room on the top floor. Go all the way up, get off the elevator, go down the hall, turn to the left, and go down a hallway. The door should be on the right, almost middle of the hall."

"Thanks; anyone on that floor?"

"No"

Sirius stuck the phone in his back pocket, then took a deep breath, and focused on his magic. As he fed off its energy, Sirius took the stairs to the top floor, taking only ten minutes to get there. He texted Remus to make sure the floor was still clear before leaving the stairway and headed down the hall, turned left, went halfway down the hall, and found the door to the storage room on the right. It was locked, so Sirius had to open it using an unlocking charm, walk into the room, remove the cloak, slug it on his shoulder, close the door back, flip on a light, and frown. This room was empty except for old pieces of Iron Man suits, he quickly texted Remus back and got the location to another storage room, a floor below, and Sirius went there. No files were there either.

Sirius ended up having to go to four more storage rooms, all the while texting Remus for directions and asking if anyone was near him; after being in the building for about an hour, he had looked in all but one storage room and that was because it was on the side of the building not facing his hotel, so Remus wouldn't be able to warn him if anyone was near. It was risky to go there, but Sirius did, and when he opened the door, he found it full of boxes of files labeled Hydra.

"Bingo," Sirius said to himself as he locked the storage door, walked into the room, and started going throw the files, reading each briefly before tossing one aside to look at another. Some files had goals Hydra had, some had plans of weapons they were trying to invent, and most had files on people, their enemies, their allies, members of Hydra, and even people they were following and keeping track of. Sirius got the shock of his life when he pulled out a file labeled Black, Sirius.

When he opened it, he found all kinds of photos of him when Sirius was younger, pictures of him going into stores, walking down the road, as Padfoot, and even one of him working on his old motorcycle, somehow Hydra had been spying on him back years ago, and Sirius had never known it; usually, Sirius knew when someone was following him, though the only time he could ever remember someone following him was Natalie Huntsman, and now he was wondering if she had been apart of Hydra.

Sirius closed the file and stuck it in his pocket, and went back to searching the files, he would have to worry about his file another time. He can't get sidetracked now. Harry was more important. His file said they were spying on him because they were considering him for their super soldier program, and Sirius was sure that must be what Hydra wanted Harry for now. Maybe that's why they wanted his blood so that they could test it. Even if they didn't know Sirius was Harry's father, they now knew of the wizarding world, so they must have heard of The Boy Who Lived.

Sirius spent nearly two hours in that room, searching every file, and found nothing. Not a person in any of these files sounded anything like the girl he fought or her brother, these were all too old, and those siblings were not much older than the Weasley twins; Sirius ran his hand through his hair. He had failed. Sneaking into this building had all been a waste of time, and he should go back to his hotel, get his things and go back to Hogwarts. Loki might be able to come up with another way to find out who those siblings were; he missed his family, anyway.

Sirius threw the invisibility cloak on, and this time he decided to take the elevator and walked out of the room, and headed toward the stairway. He went around the corner and bumped right into a woman with strawberry blonde hair; they both fell to the ground, the phone slipping from her hands.

"What the hell?" She cried out, moving back, and that was when Sirius noticed then that his legs had come out from under the cloak.

"Shit!" Sirius cried out without thinking and reached his hand down to cover his legs, which caused the woman to scream, and start to kick at him. Sirius pulled the cloak off and glared at her. Her eyes grew wide with the sudden appearance, and she started calling for someone named Jarvis. Panicked, Sirius rushed forward, grabbed hold of her and covered her mouth with his hand.

"Shh, I'm not here to hurt anyone." Sirius said as she struggled, "Just shut up, or I'll-"

"Let her go!" A voice screamed, and Sirius looked up to see Tony Stark, along with Steve Rogers, hurrying toward him; Rogers was holding his shield up, and Stark had the glove to his Iron Man suit on his hand, holding it out toward Sirius. Then behind Sirius, Thor and Clint Barton came hurrying up. Sirius glanced at them, then back at the other two Avengers.

"This isn't what it looks like," Sirius said, letting the woman go; she ran over and hid behind Stark and Rogers. Sirius could sense Barton coming up behind him and quickly turned, grabbed the guy's arm, and brought him over his shoulder onto his back; Barton stared up at Sirius in surprise. Stark shot a small laser toward Sirius, and he jumped out of the way, and the laser hit Thor, knocking him back a few feet; Rogers tossed his shield toward Sirius, who deflected it with a shield charm, and it went flying toward the right of Sirius and stuck its self in the wall.

Barton jumped up and came after Sirius, he turned in time to stop a punch from him, but he got him with another, and Sirius ducked a third and came up and tried to flip him again. Barton spun around and hit him, and there was a little back and forth between the two before Sirius got tired of it and knocked him out with a stunner. Stark sent another blast at Sirius, and this time, he deflected it, but before Sirius could do anything else, Thor was suddenly next to him, and wrapped his hand around his throat, lifted him off his feet and slammed him into the wall, holding Sirius there.

"Enough!" Thor yelled. Sirius grabbed at his hand, and tried to pull it off his neck, he couldn't breathe; ever since finding out who Reigna truly was, Sirius had never given one thought about ever meeting Thor, but if Sirius had, being choked to death by the God that was practically his brother-in-law wouldn't have been how he imagined it.

"Thor, don't kill him. We need answers." Steve Rogers was checking on Barton. He looked up at Stark, "He's alive, just knocked out."

Sirius would apparate out of here, but if he did while Thor had hold of him, he would take the good of thunder with him, plus James's cloak was lying on the floor a few feet away. He was not leaving that behind, so Sirius had to figure out how to get out of Thor's hold, grab the cloak, apparate to the hotel, grab Remus, and get back to Britain.

"Who the hell are you, and what are you doing in my tower?" Stark demanded, "And why do you look….Sirius Black?"

"That guy Nat knows?" Steve demanded, standing, Sirius had no idea who Nat was and was sure she didn't know him, but he was too busy trying to breathe to explain that; instead, Sirius raised his knee and got Thor right in the chin, surprise he stumbled, back, dropping Sirius, who managed to land on his feet and use telekinesis to summon the invisibility cloak to him, but as his hand grasped the silvery material, something hit the side of his head and Sirius crumbled to the floor; then everything went black.

AN: I hope no one in this chapter seemed to OC, Sirius doesn't recognize Natasha Romanoff yet, because so far he's only seen her far away, he never paid much attention to the news about any of them, only what they showed of Loki, he knows her by a different name, and of course, she would look a little older, as she was only in her early twenties when he knew her for one night. I picked the last name, Huntsman for her to have given to Sirius because it sounds like a last name and is also the name of a spider.

I hope Sirius didn't seem like an idiot in this chapter, I've been trying to avoid writing him childish and dumb, as I've seen in other fics, but I needed a little drama outside of what was happening at Hogwarts, and a reason Sirius disappears on them for a while.