I do not own Avengers or Loki. Sadly.

"I'm starting think I should keep getting captured just to see the imprisonments you mortals come up with," Loki smirked, watching Thor and Director Fury glide away slowly on their hoverpad.
This was definitely more interesting than what they had locked him in before, Loki thought, his gaze sliding around the new form of jail for him. The domed ceiling far above him was transparent, but probably made of something much stronger than glass.
'As if they thought I would reach it,' Loki growled in his mind.
It was what was below him that he had to worry about. Apart from the small floating platform upon which he stood, there was only darkness beneath. From the edges of the dome, smooth steel pressed against the walls of what appeared to be a bottomless pit.
"Twenty rows of three-foot spikes at the bottom," Director Fury said coldly. He and Thor were at the edge of the pit, ready to unlock the door and leave. "If you don't believe me, go throw yourself down there to check," His voice echoed along the metal walls. Loki said nothing. He was glaring at his demi-god 'brother', who matched his gaze with the same intensity.
'We are not brothers' Loki thought, wanting so badly to shout at him. Thor seemed just as angry, but there was disappointment in his face as well, which made Loki even more enraged.
'How dare he still look at me like I'm nothing but a mess, a stain on his precious Midguard. How dare he treat me like a kid!' Loki found himself on the verge of growling, snarling with anger, and calmed himself immediately. He couldn't look unhinged and incapable, like a child throwing a tantrum. For the time being, he needed to be one step ahead of these Avengers. And if he wasn't, he would need to act like it.
Director Fury clicked a small button on his control pad, and Loki felt the heavy metal bracelets on his wrists fuse into handcuffs. His left wrist was bent uncomfortably, and it didn't feel like he'd be adjusting it any time soon.
Fury punched a code in the control panel and the heavy iron doors slid open. He stalked out, into a dimly lit tunnel, not looking back. Thor stayed only moments longer, pausing just to look back at Loki with disappointment that mirrored Odin's tired face. Loki scowled at him.
"You are not my father, Thor!" He hissed. "And you're not my brother either,"
Thor turned away and walked in the direction Fury had gone. Loki only glimpsed the crimson of his billowing cape before the doors slid shut once more.
Loki had, for a third time, returned to Midguard; this time as unnoticed as possible. Or so he had hoped. But again, Loki was taken captive under SHIELD control.
This time, it was different. Loki could tell these Avengers were no longer a thrown-together group of 'heroes'; creating a disturbance among them would be difficult. And even if he was able to destroy the ties of their team, it would still leave him in captivity. Unlike on that giant airship, Loki had no close contact with the Avengers, no way to get close to them here.
He was, pathetically, without a plan.
Loki sat, cross-legged, on the cold metal serving as his lifeline. It was nearly long enough for him to lay down on if needed. But he didn't. Loki just stayed still, trying to appear expressionless. It was clear that cameras were probably watching him, recording with actions with lifeless eyes. Loki could not afford to be in the disadvantage. One step ahead... One step ahead...
Smooth metal all around. If he were to jump, Loki wouldn't make it to the edges. And even if he did, with handcuffed hands, he wouldn't be able to take any handholds.
No, direct escape was not Loki's forte. It was the mind manipulation that saved him from getting his hands dirty.
But Fury was taking that precaution. Chances are, the only contact with the outside world was going to be through the video cameras.
Loki let loose the smallest of sighs. Patience. If escape wasn't possible now, it would be later on. Patience...

It had to be at least a day later when Loki's eyes and ears caught on the sound of the iron doors opening. He raised his head slowly, expression indicating not surprise or question but a slight of amused boredom. It became hard to retain this expression when he saw who entered the room. He had been taken by surprise.
No one he knew. Not the Avengers, not Director Fury. A young woman. Long, straight, dark brown hair. Skin pale enough to rival Loki's ivory complexion. He had seen her before, watching him being led to captivity, a large black sketchbook tucked under her arm. It was with her now, and she held it protectively in one arm against her chest.
Loki couldn't see from here, but he knew her eyes were black and wide. Eyes of prey, fearful and nervous. Fear mixed with something else. It was the type of eye Loki wanted to see in his subjects. Fear was a friend to power. Your subjects fear you, they do what you say.
Loki opened his mouth to say something, but the girl nervously held a finger to her lips. It was the strangest thing. She wore a SHIELD outfit, but she appeared to be doing something she shouldn't be. Helping him, maybe? If so, it was in some weird way Loki could not identify.
She was drawing. Her sketchbook was open, and a pencil was dancing lightly across the blank pad. Loki was at the wrong angle to see what was appearing on the paper, but from the way her eyes darted to the walls, the dome, to him, she could only be sketching the scene in front of her.
"You snuck in here... To draw a picture?" Loki smirked, amusement playing across his face. Mortals. He'd never understand them.
She tapped her finger to her lips, plead in her eyes. Loki smirked again, but kept silent. Cameras. He couldn't care less if she got caught, but he did want to see how this played out.
Her picture must have been pretty damn accurate. She kept looking back at Loki, studying his face for a few frightened, but curious moments, before yanking her head back down to the page. Half an hour passed by with no let up in the scratching of lead on paper.
Never had Loki felt so impatient. Something was happening; there had to be a reason for this girl, apart from a picture. This wasn't getting him anywhere. Besides, if she wanted to draw a picture, couldn't she have looked at the camera footage?
Maybe Fury was trying to get something out of him, but Loki could not see the angle he was playing. Another ten minutes slipped by. Loki began to abandon hope of interesting events.
The sounds of sketching fell silent. The girl was looking from her sketchbook to Loki, her eyes flitting around beneath long, dark lashes. She added a couple light lines, erased something, and then just stared. Stared at the drawing, liked in some form of trance.
Loki's fingers were twitching. He did not want to wait here. Personally, he wanted to see his picture. Bit of a vanity thing, but he hadn't been around mirrors for awhile. Pictures were a step in the direction of statues, after all.
She stood up, her eyes still on the paper. Loki remained motionless, watching her with a furrowed brow. She wasn't leaving... She had her hand on the page and was surveying the scene in front of her. And then her hand and the sketchbook glowed blue.
This caught Loki's attention. Magic? Was this slight of a mortal really capable of magic?
The glowing faded, and Loki looked around. Nothing had changed. Well, that was a bit of a disappointment. Maybe the glowing was just some light trick.
The girl had changed though. She had lost a lot of the nervous demeanor and began to sketch something quickly on the next page. In under three minutes, she finished and had her hand on the page again. More blueish glowing, and this time...
Loki raised an eyebrow. A row of white platforms appeared across the gap between the girl and Loki.
The god stood quickly, looking at this new bridge to freedom. The platforms were strange. Paper white, no logos or design whatsoever. The girl hadn't pressed any buttons. She had just... Loki's eyes widened. She had drawn them.
He watched in mild amazement as the girl ran across the platforms. Unlike Fury's hoverpad, they didn't sink slightly under her weight. They were as still and solid as regular ground.
Loki could only assume she was getting him out. So, without having to be told, he turned and held out his handcuffs to her. She pulled out something that resembled a narrow, but long, cleaver. For some reason, it could hack through the metal. Maybe some other magic device.
"Cameras?" He asked softly, feeling the knife begin to make it through the cuffs.
"Covered." She said. Her voice was soft, low, but had an assured edge that Loki was surprised existed in such a timid looking girl. Her pixie size didnt help; he was at least five, maybe six inches taller. The handcuffs clattered from Loki's wrist, a twisted mess of metal. He kicked them in disgust off the edge of his platform. The knife the young woman used glowed blue in her palm and then vanished.
"They will only see this," She held up the picture she had drawn. Loki saw himself, sitting cross-legged on the platform, his back hunched but eyes bright and defiant under his eyebrows. "Just a projection of what Fury expects to see," The sketchbook glowed blue again. Loki looked to see an identical of himself sitting behind them. Much like his projections, it was not solid. It was just sitting there, like he had been moments earlier.
"What is that?" Loki asked, indicating the book.
"A sketchbook," She said simply.
"And what are you?"
"An Artist," It sounded like much more than a skilled drawer, the way she said it. A being, a spirit. Something with significance.
"Clearly," Loki nodded. The sketch was very professional, even by his standards. She smiled in thanks, then flipped back a couple pages.
On the left page was a drawing of a SHIELD agent uniform, identical to the one she was wearing.
"You drew yourself an outfit?" Loki asked. She nodded, but was paying attention to the right side picture. Another SHIELD agent outfit, but specifically one the pilots wore. She placed her hand on the sketch, and it glowed blue.
Loki felt his leather clothing shift into the slightly tighter, more uncomfortable SHIELD agent outfit. The pilot's suit came with a helmet with a tinted visor. As he walked out, no one would see his face.
"You've thought this through," Loki admired. She smiled again, but her eyes still avoided his. Modest girl.
"You didn't seem like you had a plan" The young woman countered, with a hint of a Scottish accent. Not much, just a small edge.
Loki didn't deny the truth, he had not had a plan, but decided not to confirm this. He lowered the visor and followed the girl across her bridge to the door. She opened her sketchbook to the page of her most recent drawing. Next to Loki's captivity was a row of five, hastily drawn, platforms. She erased these, and the platforms disappeared in a smoky mist. Like graphite. It was interesting…
"Follow me," She motioned, walking out the door with Loki close behind. "We're going to the hangar. There's a quinjet waiting," Now the pilot outfit was making even more sense. But this was perfect. He had an ally stationed in Los Angeles. She could easily fly him there, and he would return to the previous plan, the one he had before he was recaptured.
She led him through a series of passages and doors before finally they reached a set of stairs leading to the hangar. No one cowered in fear as Loki walked past them. Nobody leaped to arrest him and return him to his jail. He was just another pilot. Personally, he didn't like it quite as much.
They boarded a quinjet, with the girl at the main controls. She flipped some switches, pulled some controls, and some other mortal complexities Loki couldn't identify. The point was, they flew out without trouble. They were out of SHIELD control. Loki was free.