A/N: Hey, everyone. Today, we're celebrating the awesomeness that is Frea O'Scanlin, which is why I wrote this little story.

That also means, Frea, that shenanigans are probably ahead, because, well...do I really need a reason? If so, I'm blaming your brain, it can be scary—a side-effect from genius, I believe—so I tried to keep up. Or, maybe I'm just incapable of writing anything serious. Your pick.

In any case, I enrolled your sidekick, mxpw, in this adventure so that he would use his super beta skills. He fantastically did, as always. Thank you, BetaMax! Who better than a superhero to beta this story? Seems quite fitting. Oh, did I forget to mention it? There might be superheroes in this story. Maybe. Sort of. :)

I also unsurprisingly need to thank JoeltotheD. Thanks for your help, Joel.

Happy birthday, Frea!


Chapter 1: Assemble the Party

Olivia's black boots squeaked under the hallway's linoleum. She should have waited to put on her jumpsuit; the leather clothing wasn't the most comfortable, though Peter had seemed to appreciate it, at least.

"Come on, it could be fun," he told her, squeezing her hand.

"Sure."

He chuckled. "Walter is going to have a blast."

That, she had to admit, made her smile.

"Walter?" Peter asked, as soon as he and Olivia entered the lab. "Are you ready?"

"Son, come take a look at my suit!"

Peter gave Olivia a childish, excited smile and freed her hand to get down the stairs toward his father's current work station. "It is a fake suit, right?"

Olivia knew he was only half-kidding. They were hoping Walter hadn't added any real superhero features to his costume, but they hadn't had the time to make sure. Looking at the red and gold suit from a distance, Olivia thought that it seemed fairly accurate—and impressive, worryingly so. Her eyes swept the room in search of Astrid as she walked in, and she caught sight of something else.

"Walter, what, um…what happened to Gene?"

"Isn't that obvious? She's The Hulk, of course!"

Astrid walked out of her office. "Hey, guys." Their teammate was wearing a black long-sleeved shirt, black pants, and black boots too, but they were more military-styled than Olivia's. Between Astrid, Peter and her, they were a real party, all wearing black. "I tried to stop him."

That would explain the pool of green paint accumulated around Gene's feet. The cow's body was entirely covered in green. Walter hadn't painted her head, so Gene was wearing a green mask, as well as some kind of ripped pants that covered her back feet—Olivia guessed it was supposed to complete The Hulk outfit.

Peter moved to rummage through a closet. "You're not taking Gene to the party, Walter."

"Is that even safe?" Olivia asked. "The paint?"

"Of course, it's safe!" Walter said. "And we're all going, aren't we?"

Grabbing two plastic bags, Peter said, "Yes. All we humans are going."

"But—"

"No pets. Did you do something to this?" Peter said, taking out his quiver.

"We can take a picture with Gene before leaving," Astrid told Walter. "If we hurry."

"Marvelous idea, Arrow. Go fetch my Instamatic."

"Or," Peter said, "the new camera I bought you." At the look Astrid gave him, he went on, "Which I'll go fetch, of course."

"Thank you," Astrid said.

Peter gave Olivia one of the plastic bags on his way. She had her own accessories to add in order to complete her costume, though she wouldn't be covering her blonde hair with a red wig.

"Any word from Lincoln?" Olivia asked.

"Who?" Walter said.

"Agent Lee. Blond with glasses? Plays chess?"

"Oh! Remarkable chess partner."

"He sent us this report," Astrid said, handing Olivia a file, "but it doesn't sound like they've learned anything we didn't already know. You think the attacks will resume? It's been a month."

A month had passed since the last incident, and they still had no clue about who was behind it, or why. Even if no civilians had been hurt so far, the nature and danger of the three incidents were worrying and the unknown surrounding them even worse.

"They probably will." Olivia skimmed the file. "Still no word on who the birthday boy is?"

"Maybe it's a birthday girl," Astrid said.

Olivia tilting her head to the side in agreement. "I'll take that as a no."

"I've got it," Peter said, rejoining the room, and taking off his pea coat. "Come on, everybody in costumes, or we're going to be late!" He put his sleeveless jacket on. "Did you do something to this, too?"

"Only to make it more authentic, son."

"That's what worries me." Peter turned to Olivia, and ran a hand over his chest to smooth his jacket. "How do I look?"

"Well…" Olivia paused, both for effect and also because she was mostly just ogling her boyfriend. "Clint, I think I'm starting to like our choice of costumes."

Peter's smile reached his eyes in a gleam. "Me too."

—A—

Peter turned in the passenger seat as Olivia pulled over. "You and I will wait in the car, Walter."

"Why?"

"You're not wearing pants."

"I know I'm not wearing pants, Peter, but I can put my suit back on."

"I can stay with Walter," Astrid said. Olivia saw Astrid's jerk of the head in the direction of the DVD player emplaced behind Peter's seat in the rearview mirror. "And we can finish our Sponge Bob episode."

"You sure?"

"Mhm."

"Okay, well, shall we?" Peter told Olivia.

Since The Bridge facility was more secure than even the Helicarrier probably would be if it actually existed, it was for the best that Olivia and Peter didn't have to explain why Iron Man was with them, especially if Walter had added a surprise or two to his suit, which they still hadn't ascertained. They expected Lincoln, but Agent Broyles was the one waiting for them. Both of them came to a halt upon seeing him, and it took all Olivia had not to let out the smile—or more—tugging at her lips.

Broyles was wearing Captain America's Stars and Stripes uniform in all its glory: The blue tights, the red gauntlets and boots, the belt, he was missing the mask and shield, but it was enough of an image. As disturbing as it was to think about her boss in that way, he didn't look bad in it either.

Olivia thought that her boss muttered something about Nick Fury, but she couldn't be sure, and he greeted them when they finally approached.

"Sir," Olivia said.

"Agent Lee should be here any minute," Broyles said. "Have you read his report?"

"On the way," Peter said. "Walter might have a theory. We want to make some tests tomorrow."

Broyles pursed his lips. "Keep me informed."

The door behind Broyles opened, giving view to Lincoln. "Hey, guys." He sounded a little out of breath. Olivia watched as he took in Broyles' appearance, made his cape twirl as he turned to Peter in his sleeveless jacket, and her with her coat open, letting her jumpsuit and Black Widow belt buckle show. "Aww, nobody told me you were all going as Avengers. You just said superheroes!"

"Two guys in tights is kind of awkward," Peter said, looking at Captain America, before switching back to Lincoln. "How do you like it over there in the DC universe, Kent?"

Olivia suppressed another smile. Had nobody given Lincoln any details about their costumes at all? Olivia hadn't, but she thought someone would have. Oh, well. He had always struck her as a Clark Kent type anyway. His Superman suit fit.

"ETA on the party?" Broyles asked.

They literally were waiting for party goers coming from the other universe. Someone—and they had no information on who, not even Broyles—had wanted to celebrate his birthday in an exotic location, more specifically in another universe. It must have been a very important personality, high on the governmental hierarchy, for it to actually be happening. Fringe agents from both sides had been mobilized for the occasion, ensuring the safety of all involved. In that order, they were all guests, and naturally, the party wasn't just any birthday party, it was also a costume party.

"Five minutes," Lincoln said.

—A—

Olivia sipped on one of the fancy cocktail that the waiters had been serving. "I still can't believe this is actually happening."

"At least they said no about Greece," Peter said.

The birthday…person had requested to go to Greece, of all things, at first. Apparently, the Acropolis wasn't as well-preserved on the other side. Fortunately, it had been decided that they would have to stay in New York City if the party was to happen.

"It is kind of ridiculous," Agent Dunham said. "Though, they did keep information pretty tight. We don't even know who it is either."

Joining the three of them, Captain Lee extended a glass of water to his colleague, before glancing at Olivia. "Doesn't White Widow have red hair?" Three pairs of eyes shot him a look. "Right," he chewed on his lower lip, "awkward."

Peter questioningly mouthed, "White Widow," to Olivia, which she replied to with a brief shrug, though she couldn't help but smile at his obvious disapproval. He shook his head, and broke the silence. "So, Luke Skywalker and Mara Jade," he said. "That's an interesting choice."

Olivia had recognized Captain Lee's costume, but not her counterpart's. Her Star Wars knowledge stopped at the movies—or rather, her universe's movies. She had opted to give the Bishops a father-son movie night when they had planned on watching the sequels.

"They were badass in Episode IX," Lee said, "you've got to admit."

"I know!" Peter said. "Thanks again for that by the way. Walter loved them. The sequels are so much better than our prequels."

"No worries. Where's Mantis?" Captain Lee asked Agent Dunham.

"Grabbing drinks with Superman. Which, by the way, is also an interesting costume. For all sorts of reasons." She gave Captain Lee a look over, and grinned.

Unlike Olivia, her redheaded counterpart apparently didn't have any problem thinking of her boss in that way. Although, Captain Lee appeared like a confident guy, and even a little arrogant, at times, Agent Dunham's comment still reddened his cheeks slightly, and Olivia had to hide her smile behind her glass.

Peter cleared his throat. "Who's Mantis?"

Olivia had heard someone calling their Charlie this, on their way into the building where the party was being held. "Agent Francis," she said.

"Oh, right. The insect guy. I'm sorry, but can I?"

Captain Lee frowned in confusion, visibly not following what Peter was pointing at. Agent Dunham chuckled and unfastened her own lightsaber, before handing it out to Peter, who asked whether it was safe or not. She assured him it was, and the hum of the fake-weapon was rather well-done, Olivia thought, when Peter switched it on and started moving around.

"Shouldn't Agent Francis be Spider-Man?" Peter asked, between motions. "You know, with his…condition."

"Spider-Man?"

"You don't have Spider-Man?"

"Uh-uh."

"Aww, that sucks."

"Charlie's girlfriend is a bug girl," the other Olivia said. "Probably why he's Mantis. I think, in his case, the real party will start when he'll get back home."

Peter's laugh transformed into a choke when Olivia elbowed him and discreetly indicated him in Nina Sharp's direction. Not only was Nina talking with Broyles, who had now put on his Captain America mask and was holding his shield, which was enough to make any Fringe agent choke tonight, but Nina was wearing her own outstanding costume. A red cape was draped around her shoulder, above her grey armor. The gauntlets seemed a little shinier than necessary; it seemed that some diamonds had been added. And the hammer in Nina's hand was imposing.

Maybe sensing the attention, the woman turned her blonde-wigged head toward their little group and lifted her cocktail in greetings. Olivia and Peter returned the gesture.

"I guess we're only missing a Loki, now," Olivia said.

"Oh, we have one." Peter looked around the room. "Our Scotland Yard liaison, the one who's got a twin."

"Agent Simon?"

"Yeah." He lowered his voice. "I think his sister is a spy or something, he's very evasive on the matter." Olivia's skepticism must have showed, because Peter dropped the subject, and looked around again. "I can't find him now. You can't miss him, though, he's got the gold Viking helmet and everything. Oh-uh, Walter's at the buffet."

"I guess that's our cue," Olivia said, before she and Peter excused themselves. Passing one of the numerous yellow and blue costumes of the party, Olivia spun back around after a few steps. "I meant to ask," she told the other Dunham and Lee. "What's with all the minions?"

—A—

"Maybe you should have been Iron Man," Walter said to Nina in a tone of confidence, "you already have the arm."

"Walter!" Astrid said.

"It's okay," Nina said. "He isn't wrong. Though, I can't fly yet."

"With the suit, you could," Walter said.

"But you can't, right, Walter?"

"No, son, I couldn't add the flying features on such short notice."

They had received the "party invitation" the previous weekend. Walter had been watching Iron Man 2 at the time, hence their costumes.

Olivia shared a worried look with Astrid and Peter. She would have thought that Astrid's eye patch—she had completed her costume once they left the lab, and was also wearing Nick Fury's black leather coat—would have made it difficult, but her colleague's expressions were clear.

"Your Thor impersonation is excellent. May I?" Walter pointed at Nina's hammer. The swooshing sounds of the Iron Man suit were still a little unsettling.

It had taken them all by surprise at the lab earlier, when Walter had put on the suit to pose for the picture with Gene. He had powered up the suit, and…it'd moved. Now, Walter wasn't wearing the helmet because it clashed with Walter's appreciation of the buffet, which took some of the effect of the suit away, but anyone that knew Walter would still be on their guard about the rest of the costume.

Olivia scanned the room. There hadn't been any incidents with the trip from the other universe, no journalists to ask questions, no birthday person to recognize either, for that matter. She was starting to wonder if the party really was a birthday celebration. Her eyes stopped on Agent Valley walking stiffly toward Broyles across the room. He whispered something to him, and his eyes traveled among the attendance, concerned, until he spotted his group of Avengers.

Olivia separated herself from the crowd with a few steps as her boss approached. "Sir?"

"We have a situation," Broyles said. "There's been another breach." He didn't waste time giving her more details and asked Olivia to bring her team to a conference room in the building for a briefing, before hurrying in the direction Agent Valley had left.

Following the news, Peter looked at Astrid. "You should say it, Fury," he said. Astrid's brow furrowed as Walter smiled at his son, his eyes sparkling. At Astrid's silence, Peter went on, "Fringe Division, assemble."