Disclaimer: I own nothing to do with the Harry Potter or Marvel franchises. There is quite a lot of borrowed dialogue from the first Avengers film in this story – none of which I own, either!

A/N Hi guys! I'm back! I told you I wouldn't be long. I've been desperate to post this ever since I watched Age of Ultron last week but I've just been too busy! Until now…

Warning to new readers – to avoid confusion, I highly recommend that you read the first story in this series, Hermione Granger: Agent of SHIELD. This story starts immediately after that one finishes.

By the time Nick Fury arrived at the Project P.E.G.A.S.U.S. facility in the Mojave Desert, Hermione Granger was in a very bad mood. She'd been summoned to the site's coordinates by Agent Coulson three hours previously and had been more than surprised to discover the secret S.H.I.E.L.D.-and-NASA-run base. What had been an even more disturbing sight, was the little, blue cube deep in the bowels of the facility that was making everyone quite flustered.

"But I thought it was lost in the final altercation between Captain Rogers and Schmidt?" she questioned, turning to Coulson, who had escorted her down.

"Howard Stark discovered it at the bottom of the ocean in nineteen forty-five," he replied, as they watched scientists in white lab coats hurry between various machines.

Hermione frowned. That bit of information had definitely been omitted from the report she'd read nearly a year ago. She had a feeling that Fury had specifically kept her in the dark about the Tesseract and suspicions whirled around her mind at the motives he may have had.

"Well, what am I doing here, then?" she asked. "I don't see how I can be of any use when you've got a whole team of scientists at your disposal; I know next to nothing about the Tesseract."

"There was a huge energy spike from the cube about an hour ago," Coulson explained. "It was completely spontaneous; no tests were being run at the time and now those energy levels are rising. Our lead scientist, Dr Selvig, has tried shutting it down but apparently nothing is working. If the situation doesn't improve soon, we will issue an evacuation."

Hermione appraised the man who seemed to be issuing all the instructions. When she had met with Jane Foster a few months ago to discuss Thor and the Nine Realms theory, Jane had spoken incredibly highly of Dr Erik Selvig. If S.H.I.E.L.D. had put him in charge of this research, then Hermione trusted that he knew what he was doing.

"You want me to see what impact my magic would have on it," she stated, not particularly thrilled at the idea. One of the scientists probed at the Tesseract with some sort of technical instrument and the cube spat out a surge of blue energy, making him step back in alarm. "Have you considered that I might make it worse?"

"Yes, but Fury wants you to try anyway," Coulson replied, ushering her to the middle of the huge laboratory. "We really haven't got a lot of options. Dr Selvig," he called, making the doctor turn. "This is Agent Granger. She's going to be running a couple of tests of her own on the Tesseract – Director's orders."

Dr Selvig didn't look very happy with that statement and Hermione tried not to be intimidated as he looked her over. "What sort of tests?"

"Magical ones," she replied simply. Hermione doubted that if Selvig hadn't had a previous run-in with a god from another world, he would have been so accepting of that answer.

"What do you need?" he asked instead.

"I think it would be best to have as few people here as possible," she said. "There's a strong possibility that my tests will only make the situation worse."

Dr Selvig nodded and started telling his team to move out.

"You might want to fill in Agent Barton on what you're planning," Coulson suggested, indicating far over his shoulder to where the wall and the ceiling met. When Hermione squinted, she could just make out a little figure perched, watching the proceedings.

"I'll be back in a minute," she said, before apparating next to Barton.

He flinched at her arrival. "Give me some warning next time," he muttered, not taking his eyes off the Tesseract.

"Sorry, it's quicker this way," she explained, taking a seat alongside him. "Um, hello, we haven't been properly introduced."

He spared her an unimpressed glance. "Really? You want to do this now?"

She was glad that he wouldn't be able to see her blush in the dim light. "I don't want things to be awkward between us after Anchorage."

"Why would that be awkward? We were just doing our jobs," he pointed out. "I'm actually pretty proud of the fact that I've got the record for holding out against the Sorceress for the longest: twenty-one seconds."

Hermione's eyes widened in surprise and she wasn't quite sure how to respond to that comment. "Oh! Well, Fury wants me to run some tests on the Cube to see if I make things better. You can wait outside if you…" He sent her another flat glance. "Or, okay, just stay here." She apparated back down to the floor and found that only Coulson and Selvig remained. "Are you sure you want to stay? I really don't know what's going to happen."

Neither man moved.

She approached the Tesseract tentatively and drew her wand from inside her jacket. A complicated machine was keeping the Cube held in place. From what she'd seen, the Tesseract didn't like being approached by anything else so she hoped that Selvig's contraptions wouldn't find any of her magic too interfering. Taking a steadying breath, she sent and maintained a basic shielding charm to wrap gently around the cube to try and dampen the interference it was radiating.

The misty, white light contracted around the Tesseract as the readouts from the machines fluctuated and the lights of the lab flickered. When the perimeter of the shield was only a couple of inches away from the surface of the Tesseract, a burst of energy shot from it, racing along the path of the magic, back towards her. It all happened so quickly that she had no time to defend herself as it blasted her backwards into one of the lab's machines, knocking her out.

"How bad is it?" Nick Fury asked Agent Coulson when he and Hill had stepped out of the helicopter.

"That's the problem, sir," Coulson replied, removing his sunglasses. "We don't know." He started to escort them down to the laboratory. "Dr Selvig read an energy surge from the Tesseract four hours ago."

"NASA didn't authorise Selvig to go to test phase," Fury pointed out.

"He wasn't testing; he wasn't even in the room," Coulson explained. "Spontaneous event.

"It just turned itself on?" Agent Hill said in surprise, half a pace behind Fury and Coulson.

"Where are the energy levels now?" Fury asked.

"Climbing," Coulson replied. "When Selvig couldn't shut it down, we ordered evac."

"Agent Granger wasn't able to help?" Fury enquired with a frown, as people hurried past him with large metal containers.

Coulson shook his head. "Afraid not, sir. The Cube's energy launched her across the room after only one spell. She was out cold. The medics have already gotten her out."

Fury nodded to show his understanding but he was disappointed that, for once, Granger couldn't save the day. The possibility that her magic and the Tesseract's energy wouldn't mix well was one of the reasons he'd kept its location hidden from her in the first place. "How long to get everyone out?" he asked.

"Campus should be clear in the next half-hour," Coulson responded.

"Do better," Fury ordered. With a nod of the head, Coulson left.

After ordering Hill to make sure the Phase 2 prototypes were shipped out and hearing the concerns of Dr Selvig, Fury spoke with his agent on the scene – once Barton had descended from his 'nest', anyway.

"I gave you this detail so you could keep a close eye on things," Fury reminded him as they walked towards the Tesseract.

"Well, I see better from a distance, anyway," he replied simply as one of the scientists warned of another energy spike.

"Have you seen anything that might set this thing off?" Fury asked.

"No-one's come or gone as far as I can tell. But we both know that eyesight isn't as reliable as we once thought it was…" Barton said, his meaning left hanging between them.

Fury frowned and put his hands on his hips. "If you suspect Agent Granger, just come right out and say it."

"Selvig's clean," Barton stated, not intimidated by the Director's tone. "If there was any tampering at this end, sir, it can only be her."

A loud crack resounded in the lab and both men reached instinctively for their weapons, as did the other armed agents in the room. However, they quickly saw it wasn't necessary when the sprawled form of Agent Granger rolled across the ground a few feet away. She shook her head, as though dazed, and Fury walked forward to pull her to her feet.

Granger looked up at him with panicked eyes. "Sir, I know what's going to happen!" she cried. The moment the words were out of her mouth, the room started to shake and the Tesseract forced out another wave of energy.

"The door is being opened from the other side of space," Agent Barton stated and Granger nodded.

Another, more violent, burst of blue light came from the Cube. Others followed, growing increasingly powerful. All they could do was watch and wait, as a blue beam of energy burst from the Tesseract to the back of the laboratory. It certainly looked like a door to space, Fury decided, seeing the dark black hole that was being formed by the Cube's energy. The question was: who or what would be coming out of it?

All of a sudden, the energy creating the door exploded outwards at them all. Thankfully, although it was blindingly bright, it caused no great harm.

Fury looked back at where the door had been and saw a figure crouched there, steam rising from it.

"What do we do, sir?" Granger whispered, a tremor in her voice, as armed agents hurried forwards, their weapons trained at the arrival.

"Hold steady, Agent," he replied, watching the figure slowly rise. Even from a distance, Fury could see the menacing grin on the man's face. In his right hand, he held a long spear and, at the top, it glowed a similar colour to the Tesseract.

"Sir!" Fury called to him. "Please put down the spear!" He didn't hold out much hope for a diplomatic agreement with the newcomer but it was worth a try.

The man looked at the sceptre in his hand, as though only just noticing it was there, before shooting a burst of energy at him. Barton and Granger pushed Fury out of the way and took up attacking positions, as the sounds of gunfire echoed around the room. Fury watched as the stranger worked quickly to incapacitate his men; blasting them with energy, throwing knives and stabbing them with his spear. When Granger fired her first spell at him, he ducked out of the way and showed her a look of surprise. She launched a tireless attack on him, different coloured lights illuminating the room. The newcomer had to move quickly to avoid them but one spell caught his left hand, slicing into the skin and drawing blood. Anger flashed in his eyes and he shot a sustained beam of energy at her. Granger erected a shield but Fury could quickly see that it was failing. The stranger let out a cry of triumph when she was thrown backwards, landing a few feet from Fury. His initial concern was lessened when he saw her breathing shallowly and her eyes blinking.

Hearing a disturbance, Fury looked up. Agent Barton attempted to attack the stranger again but the man held him firm.

"You have heart." They were the first words the newcomer had said. He pressed the tip of his spear to the matching point on Barton's chest. A blue glow flowed from the sceptre into Barton, and Fury saw the agent's eyes turn completely black. A second later they had cleared, although his irises matched the colour of the spear. Though what was most alarming of all, was Barton returning his gun to its holster and looking to this man for orders. The sceptre must have some sort of brainwashing power.

Glancing around, Fury realised he had to get both the Tesseract and Granger out of there.

Fury quietly pulled the Cube out of Selvig's machine while the stranger brainwashed a different agent, and he made eye contact with Granger. He pointed at the Tesseract as he sealed it away inside a specially designed brief case, then at her, followed by mouthing the word, "Go!" He stood, intending to pass the case to her.

"Please don't," the stranger called softly. "I still need that."

Fury paused, shielding Granger from sight as she lay on the ground with wide eyes. Patience, he told himself. Wait for the perfect moment to give her time to get away. "This doesn't have to get any messier," he said over his shoulder.

"Of course it does," the man replied calmly. "I've come too far for anything else." Fury turned around to look the man in the eye. "I am Loki, of Asgard, and I am burdened with glorious purpose."

Unfortunately, that was a name that Fury was familiar with. The Asgardian had brought enough trouble to earth last year and he hadn't even stepped foot on the planet!

"Loki!" Dr Selvig repeated, getting to his feet. "Brother of Thor."

Loki didn't look particularly pleased to hear a mention of his brother and he threw a seething look in Selvig's direction.

Fury raised a placating hand. "We have no quarrel with your people."

"An ant has no quarrel with a boot," Loki replied imperiously.

"Are you planning to step on us?" Fury asked, keeping his voice calm.

"I come with glad tidings," Loki insisted, walking casually across the lab. Fury tried not to tense as Loki got slightly closer to Granger's position. "Of a world made free."

"Free from what?" he asked, wary of Loki's light tone.

"Freedom," Loki replied simply. Fury felt his blood boil at the Asgardian's words. "Freedom is life's great lie. Once you accept that, in your heart…" Loki spun and turned his spear on Dr Selvig, the now familiar transformation taking place in his eyes. "…you will know peace."

Fury twisted and threw the briefcase to Granger. She caught the case against her chest, twisted and disappeared with a loud crack.

Loki looked around in surprise.

"Yeah, you say 'peace'," Fury said, feeling a lot more relieved. "I kind of think you mean the other thing."

Loki glared at him. "It appears that the ant has rather a bite to it," he said but his tone wasn't as worried as Fury had expected it to be.

"Sir, Director Fury is stalling," Barton stated, walking over to his new master. "This place is about to blow and drop a hundred feet of rock on us. He means to bury us."

"Like the pharaohs of old," Fury crowed.

"He's right. The portal is collapsing in on itself," Selvig confirmed, looking at one of his computer screens. "We've got maybe two minutes before this goes critical."

"Well, then," Loki said, with a glance to Agent Barton. Barton raised his hand and shot Fury in the chest, knocking the Director onto his back. "Let's go get my Cube. And who knows, maybe there will be an extra prize for me too."

Fury lay on his back, completely winded, as the four men walked swiftly from the laboratory. He had no idea where Granger would have taken the Tesseract but he had to try and stop Loki and the others from seeking her out. He reached for his walkie-talkie. "Hill! Do you copy?" He yanked the bullet from his body armour. "Barton's turned."

The sound of gun shots echoed from not far away and he had faith that it was a positive sign. Fury glanced up at the mass of blue light that was swarming around the roof of the lab. He had to leave. Breathing was still difficult but he forced himself to run. "They're after the Tesseract. Shut them down."

There could be only a minute left before he'd be buried under Project P.E.G.A.S.U.S. He climbed desperately, knowing that his helicopter would be waiting on the roof.

"We're clear upstairs, sir," Coulson's voice crackled through the walkie-talkie. "You need to go."

Fury stepped into the helicopter just in time, as the concrete began to crumble away a second after it had lifted. "Try and get in contact with Granger," he ordered, watching the facility disappear into the ground. "She's got the fate of the world in her hands."

It was with another rather bumpy arrival that Hermione appeared about half a mile from the Project P.E.G.A.S.U.S facility. The speed of her arrival forced her to roll along the ground a few times and the briefcase was knocked out of her arms, spinning off into the desert. She lay on her back, her mind fighting against a swirling darkness that was threatening to send her into unconsciousness again. That bloody cube was proving to be an absolute pain in the arse! Not only had it knocked her out when she'd tried her tests, but its energy had had a strange effect on her magic; seemingly making her more powerful. When she'd woken in the medic van, she had attempted to use her wand to carefully remove an IV drip from her arm, but her spell had shot the drip across the interior of the van hard enough to dent the metalwork and leave her arm a rather bloody mess.

Hermione hadn't paid this much mind though, because she'd known how important it was to warn the others about what was coming. She didn't understand how, but it was as though the Tesseract had communicated with her, passing on knowledge about itself. The doorway was being opened from the other side of space and it couldn't be for a good reason. Hence, her rather scrambled arrival back at the laboratory.

Underneath her, the ground shook and she could hear a monstrous rumbling noise, but it was as though someone kept manipulating a volume dial in her head as she continued to fight unconsciousness. She forced herself to sit up. Using her wand to combat her concussion was out of the question with her magic so awry and she cursed as she realised that her jacket and all of its magically concealed contents had been taken off of her when she'd been evacuated.

Until she heard otherwise, she'd have to assume that Loki was still at large. If that was the case, then he'd certainly be seeking the Tesseract. The Director had entrusted her with keeping the Cube out of Loki's grasp. But with limited resources in the middle of a desert, malfunctioning magic and a battered body, what was her best option?

The greatest way she knew to keep something hidden was to use a Fidelius charm. The problem was she'd never cast one before! It was a difficult spell even without her magic problems but what else could she do? She could take the Tesseract to another secret S.H.I.E.L.D location but if Loki had turned Barton, then none of those places were secure any more.

There was also the strong chance that the Tesseract wouldn't want to be moved by her magic. It had reacted violently to the simple shield spell. However, that had been when it was preparing itself to open the doorway. Perhaps it wouldn't be so hostile now?

Hermione got unsteadily to her feet and lit her wand to search for the silver briefcase. The overly intense beam from her wand meant that it was easy to spot, but she disliked being this unfamiliar with her magic.

She opened the briefcase and contemplated the glowing, blue cube inside. It certainly seemed calmer now. She reached out cautiously with the tips of her finger and felt the smooth surface. A calmness came over her. As strange as it sounded, it was almost like the Tesseract was comforting her. She felt the magic within her settle. She could perform the Fidelius charm. She was going to stop Loki.

Hermione resealed the briefcase, feeling rejuvenated. In order to keep a secret, she first needed to make one. Spotting a small, twisted and gnarled tree a few metres away, she carried the case over to it. She used her magic to gouge a hole into the dusty soil. The spell was still powerful, but this time she was in complete control. When the ditch was a couple of feet deep, she carefully let the briefcase drop to the bottom before covering it with the dirt. That was the easy part.

She took a deep breath and mentally went through the magical theory of the Fidelius charm before beginning. The Tesseract is buried next to a Joshua tree in the Mojave Desert, she told herself repeatedly. She started making the required intricate wand movements and felt a flurry of excitement as the expected series of glittering, golden lights floated in front of her. She continued her actions and, after a couple of minutes, she began to recite the complicated incantation for the first of seven times. As each repetition went by, her confidence rose a little more.

A searing pain erupted near her right shoulder blade.

She screamed and dropped her wand, breaking the spell before she'd had a chance to complete it. Glancing down, she nearly fainted at the sight of the black arrow that had pierced through her flesh.

Barton was near.

Hermione tried to take a step forward to pick up her wand, but her body wasn't obeying her wishes. She fell to her knees, her legs unable to support her weight anymore. A vehicle was approaching but she was beginning to black out.

Panic flooded through her. Was she dying?

The world twisted sideways as she fell to the floor.

No, this couldn't be the end! Not now! Not when they were all facing such a danger.

She glanced over to the Joshua tree. There was a chance that the Tesseract wouldn't be found, but it was only a slim one…

She'd failed and she knew it.

Hermione closed her eyes. She didn't want Loki's triumphant face to be the last thing she ever saw.

"You're certain she's not dead?" she heard him question.

"The arrow was laced with a sedative, sir," Agent Barton replied. "An arrow between the scapula and clavicle won't kill you if you avoid the rib cage and the subclavian artery, which I did." This was small relief to Hermione when she heard Barton's next words. "Are you going to turn her now and make her reveal the location of the Tesseract?"

"Not necessary," Loki replied. "The soil around that tree has been disturbed. That's where we'll find it. Besides, I want to watch her eyes change when I speak to her heart."

His words echoed menacingly in Hermione's mind as her body finally gave in to the pull of the drug.

A/N Cliffhanger! To be fair, I didn't really give you any in the first story.

Please bear in mind that I'm not going to be updating this story anywhere near as frequently as I did last time because I'm now very much back to work after my two week Easter break.

I hope you enjoy(ed) watching Age of Ultron!

Fingers crossed for an update next weekend!