Tonks stepped out onto the party deck of Avengers Tower, trying not to teeter in the high heels she'd donned for the occasion. She was greeted with a wave of noise, the music from the loudspeakers blending with the chatter of the attendees. Her gaze swept over the room, taking in all the faces and possible escape routes. The war had ended decades ago, but the habit of constant vigilance was one that never completely faded.

It felt weird not to bring a bottle of wine with her, but Stark had insisted that anyone who brought a contribution wouldn't be allowed through the front door. If it were any other day, she might have snuck something in anyway, but it wasn't worth the risk.

As much as the oversight would horrify her mother, being allowed entry was more important than adhering to dinner party norms.

'Maria!' said a redhead — Natasha Romanoff, Tonks thought, remembering the file she'd read on the woman; agent, assassin, lethal. She was standing by the bar with a man that Tonks recognised as Bruce Banner: Hulk, scientist, genius. 'What's your poison tonight?'

Tonks blinked. Was the spy so obvious as to try to kill her in front of everyone? Had they completely misread Maria's status here? But then why was her tone so friendly?

The words stirred up a vague memory of her father using the phrase once when she was young to mean "drink of choice".

'Beer,' she said, hoping it was the right answer. 'Any kind.'

Romanoff grabbed a bottle and passed it over to her, unscrewing the lid with an ease that spoke of either a propensity for drinking or a past assignment as a bartender.

'Thanks.' Taking the bottle, Tonks turned to survey the room. 'I suppose I should find Stark.'

Banner gestured to a loose circle of people standing near a line of spotless ceiling-to-floor windows, which captured a brilliant view of the sun setting over the New York skyline. 'He's over there.'

As Tonks walked in the direction Banner had indicated, she slipped the tip of her wand out of the holster she'd sewn into her jacket sleeve and wordlessly changed the beer into water. Everyone had to see her drinking; that way, they might mistake any oddness for tipsiness. But actual inebriation would be a complication she couldn't afford.

It didn't take long to find Stark. The picture of the consummate socialite, he was laughing heartily as he listened to a man whose back faced Tonks. As she drew nearer, however, she noticed a hint of wariness lurking in his eyes.

Out of everyone, his file was the one she'd poured over the longest, and it wasn't just because it was the most detailed. Given his purported ability to break into nigh-impenetrable systems, he was her best source of intel.

After observing the use of magic in the Battle of New York and the inexplicable portals that appeared across the globe a few short months later, the ICW had been concerned about the threat of discovery. MACUSA had infiltrated several Muggle government agencies with the aim of determining what, if anything, was known about them.

The nature of the agencies they were infiltrating meant they were long-term ops, with agents spending years building good reputations and working themselves up the ranks. When the first Auror finally reached a position that was senior enough to be useful, the department had celebrated.

And then S.H.I.E.L.D.'s data leaked. The Auror's information was caught up in the mess, making him a target for Muggles across the globe. The mission a failure, he and all of the other Aurors were pulled out, burrowing deep into the wizarding world to avoid detection.

For a time, they'd been stuck on how to proceed further. Then, the Ministry had proposed a new strategy, offering the use of Tonks' Metamorphmagus skills for the mission. That was the first she'd heard of the ICW's concerns; prior to that, she'd thought the Ministry was turning a blind eye to the threat. Armed with new knowledge about the history of the operation, she'd spent months perfecting Maria Hill's accent, mannerisms, and speech patterns, as well as learning to walk in the death traps she called work shoes.

Even with a Stabilising Charm on her feet, it was an effort to stay upright.

'Agent Hill, only fifteen minutes late this time!' Stark exclaimed, drawing the attention of the others. 'I couldn't believe it when JARVIS said you'd entered the lobby; I was starting to think you were trying to beat my record for being fashionably late.'

'Work kept me,' Tonks said, joining the circle between the man who had been speaking earlier — whom she now recognised as Clint Barton; archer, agent, spy — and Helen Cho: geneticist, biologist. 'We can't all set our own timetables.'

His eyes sparked with curiosity, lighting up his face. 'Anything interesting come up?'

That brought Tonks up short. Her file had warned her that Stark was arrogant, nosy, and charming enough to win people over despite his faults, but she hadn't realised how accurate that was.

Barton sighed.

'That's classified, as you already know,' she said, recovering.

'So that's a yes.' Stark grinned. 'You may as well tell me. I'm going to find out sooner or later anyway.'

Tonks raised her eyebrows. Between his cocksure attitude and the implication that he could get anything from anyone, he would have gotten along with Remus and Sirius.

It would have been pure chaos, anarchic but a blast in the best way.

'Then why would I deprive you of the challenge of working it out for yourself?'

He scoffed. 'Oh, trust me, that's not a challenge. It's just a matter of when I get bored enough to invest time into it.'

Shaking her head, Tonks took a swig of "beer" to keep herself from laughing. 'This isn't going to be strong enough.'

'Well, you know where the hard liquor is.'

'Maybe later,' she said with a genuine smile.

-x-

Tonks lay low for the first few hours, biding her time as she learned more about the group's dynamics and how Maria fit into it. Unfortunately, nobody seemed inclined to talk business, which was understandable but inconvenient.

If she was going to discover anything useful, she would have to risk bringing it up herself.

Earlier in the evening, they'd migrated from the bar to a table bordered by four coaches. They had all tried lifting Thor's hammer, which apparently had a spell on it that meant it could only be lifted by those it deemed worthy.

Hermione would have loved the chance to get her hands on it and break down the criteria a person had to meet to pass the worthiness threshold.

After they had all tried and failed to make the cut, they'd settled back into easy conversation. With the exception of Steve Rogers — super strong, morally upright, apparently unable to get drunk — everyone but Tonks was tipsy. Her trick of replacing her beer with water had kept her clear-headed, although there were times she hadn't been able to get alone long enough to make the switch.

Still, that left everything right where she wanted it. The alcohol should have loosened the others' tongues by now. She turned to Thor — Asgardian, likes thunder, the most likely Avenger to believe in magic.

'So,' she said casually, as if she hadn't rehearsed the words in her head to infuse them with the right amount of lazy interest, 'how's that brother of yours?'

'Dead.' Thor's voice was flat. 'He gave his life to save Jane.'

'Oh.'

Tonks knew grief well. Losing Remus had been devastating, and there had been times when the only thing keeping her going was knowing that Teddy needed her.

Mass murderer or not, Loki was Thor's brother. She could understand his pain.

But what about Maria? Would she apologise for his loss or be grateful that the man who had almost destroyed New York was gone? Would she speak or say nothing?

The others didn't seem to know what to say either. Stark's face was as hard as ice as he stayed uncharacteristically silent, and Barton's knuckles were gripping his beer so tightly they turned white.

Finally, Rogers set a hand on Thor's shoulder.

'I'm sorry you had to go through that,' he said. 'It must be difficult.'

Thor gave him a quick nod, but his reply was unyielding. 'Loki made his choices, good and bad. I just hope he has found some peace.'

Tonks tilted her head. 'What do Asgardians believe happens... "after"?'

'They spend the rest of time another realm. Those who die honourably open their eyes to the grand halls of Valhalla, while those whose deaths were unremarkable awaken in Hel.'

'It's based on how you die rather than how you live?' Barton asked.

'Yes. That is why so many Asgardians are warriors; it is considered the height of bravery to give one's life in battle.' Thor paused, and his eyes grew wistful. 'Our Hel is not a bad place, not like yours, but Valhalla… Valhalla is something else entirely. Its feasts and opulence are the talk of legend.'

Tonks frowned. The idea of there being different realms hadn't come up in her briefing. 'If nobody has ever come back, how do you know for sure?'

'Heimdall sees all.'

Her heart seemed to skip several beats. 'Is there anything he can't s— '

'You're telling me,' Barton cut in, his voice low and dangerous, 'that after everything he did, Loki is being rewarded because he did something right in death?'

A dark expression clouded Thor's face. 'Careful. You knew my brother for mere days. Do not speak of things you know so little about.'

'I know you're upset, but you're not the one he forced — '

'You don't know — '

'More Asgardian ale?' Rogers asked, standing. 'You said you wanted to see who can hold it better.'

Thor stared at him for a moment, his eyes distant and unseeing, before nodding and rising to his feet. 'I think you'll find that what I said was that I want to see how long it takes for me to drink you under the table.'

They left, leaving awkward silence in their wake.

Tonks' brain was whirring. She regretted the friction her questions had caused, but she was too busy considering the implications of what Thor had said to linger on that.

Who, or what, was Heimdall? Did he know about the wizarding world? Did that mean that Thor did, too — and, by extension, the Avengers? If Thor hadn't told them yet, would the Ministry be able to strike a deal with his people to protect their secret?

How could she get confirmation of that without planting the possibility of magic's existence in their minds?

'I didn't know you were interested in Asgardian mythology,' Stark said, tearing her from her thoughts. He shot her an inquisitive look that lasted a little too long for her liking.

She hesitated. When it came to her cover, she'd thought the biggest threats were Romanoff and Barton since they'd had the longest history with Maria. But perhaps her concern had been misplaced. 'I'm interested in a lot of things.'

'It's weird,' Barton said.

She'd thought her questions were sufficiently innocent... Maybe Maria had expressed disinterest in Asgard in the past?

Leaning forward to set her beer on the table, she hid her right arm under her body, ready to draw her wand if needed.

Barton continued: 'Knowing that things like that exist out there… it messes with your head.'

'You can say that again,' said Rhodes — military liaison, War Machine, close friend of Tony Stark.

'Do you think there's more than just Asgardians out there?' Tonks asked, seizing her chance.

Barton tapped his fingers against his thigh. 'I don't know. I used to think it was crazy, but now — '

'Now, it doesn't seem as improbable.' Stark shook his head. 'What I saw when I went through that portal…'

Tonks waited for him to continue, but he didn't. His eyes, haunted and unseeing, were fixed on a point off to her right. 'More aliens? Or magic?'

'Magic isn't real,' he replied decisively. 'Thor thinks otherwise, but everything Loki did was just technology that we haven't invented yet. Give me a few weeks alone with any of it, and I can work out what makes it tick.'

Rhodes cleared his throat. 'I don't know, Tony. Most of it, maybe, but some of it… Some of it didn't make sense.'

'And you think the answer is magic?'

'No. I just don't think it can't be magic.'

'What Loki did didn't feel like technology,' Barton mused.

Silence settled over the others, who seemed to be lost in their thoughts. At first, Tonks let it sit, hoping that someone would jump in and say something useful. But as time wore on, she accepted that it was unlikely.

At least she knew that the Avengers as a whole didn't know about the wizarding world, although she still had her suspicions about Thor.

'Well,' she said, 'whether it's magic or technology, I'm glad it's gone. If I never see anything like that again, it'll be too soon.'

'Hear, hear,' Barton said, raising his bottle towards her.

She went through the motions of clinking her bottle against his and taking a drink, but her mind was racing.

If Stark and Barton didn't know about the wizarding community, then chances were that nobody else did, either. Well, Romanoff might, but she probably wouldn't share it if she did; everything Tonks had read indicated that the woman was a steel trap.

Staying longer was unlikely to uncover anything else, and it would increase the risk of the operation backfiring.

'I should head out,' she said, rising to her feet. 'Fury wants me at work early tomorrow.'

'Why is that again?' Stark asked casually.

Tonks laughed in surprise. No wonder so many women had fallen for his charm. If she weren't here for a mission, she would have gravitated towards him as well. 'Still classified.'

'Still going to find out.'

'Still not going to change anyth—'

A shrill ringing cut her off, and she winced. She glanced around, then her gaze settled on Tony — he was the most likely to know what it was. But he looked just as confused as everyone else.

Low, inhuman groaning filled the room, accompanied by slow, creaking footsteps.

At the entrance stood an abomination of metal, wiring, and light. It looked like the photographs she'd seen of the Iron Man and War Machine suits in action, except it was alive.

Alive, inhuman, and utterly grotesque.