Hey everyone! Once again, I have returned from the void.

Apologies for the six-month wait. The truth is, this chapter took so long because the chapter itself is super long. It's the longest chapter of this fic yet, and since it contains the first big action set piece of this story, I wanted to make sure I did it justice.

A couple of other quick announcements:

1) I aim to finish this story before Infinity War is released in May. Whether or not that will actually happen, I don't know. But I'm stating it here so that you can hold me accountable when I screw up.

2) With the recent release of Big Hero 6: The Series, I feel that it is important to note that only the events of the 2014 movie are considered canon to the crossover universe of this fic. This is mainly due to the fact that I started this fic in 2014 (way before the television series was even announced), and a lot of the events that happen at the beginning of this story don't agree with the events of Baymax Returns. I may include a couple of characters from the series later on in the fic, but that is to be determined. I will be updating the first chapter with an author's note to reflect this.

Alright, that is it! Hope you enjoy!

o-o

Honey coughed, eyes watering behind her visor. Her ears rang with the thunder of concrete crashing to the ground; her chest stung, pressed flat against the broken ground. Chunks of rubble rained down on her back. Distantly, she could hear the faint, recognizable shuffling of Baymax's feet.

A strong hand grasped her arm. "Are you okay?" asked Steve as he helped her stand. A large scorch mark was splayed across the front of his shield—Honey fuzzily recalled the captain lunging in front of the group and deflecting the strange blue energy into the ceiling.

"I—I'm fine," she replied, gently rubbing her shoulder. Her eyes stung from the dust clouding the dark space. "A little shaken up, but fine." With another faint cough, she turned to Baymax. "Where are the others?"

The robot blinked. "My scan indicates that they are on the other side of the debris," he said, pointing at the large pile of rubble that had sealed them inside one of the room's three hallways. "I can detect no major injuries, but Gogo and Wasabi have both sustained mild epidermal abrasions."

Their comms popped with static. "Hey, can anybody hear me?" asked Gogo. Her voice broke and crackled, as if the earpiece was struggling to pick up her words. "I've got Stark with me. Where are you?"

"Me and Wasabi are in a hallway, I think," said Fred. "I jumped out of the way as soon as that big blue explosion hit."

"Baymax and Captain Rogers are with me," Honey added.

"Alright." Their comms rattled as Gogo took a deep breath. "We have to keep searching the base. Hiro and the Cube have to be here somewhere."

"I'm sorry," interrupted Tony, "but are we ignoring the maniac that attacked us with the glow stick of doom just now?"

Steve's jaw tensed. "We'll deal with him when we can. Right now, the Cube is more importan—"

"Never mind, I've got eyes on him. Catch you later."

o-o

Tony rocketed down the halls, repulsors flaring as he rounded a corner, chasing the tail of an emerald green cloak. "Stark!" a voice shouted after him. A blur of yellow and orange flashed beside him before slipping from his field of view once more.

"How can you keep up with me?" asked Tony.

Gogo ignored his question, springing forward and skating along the concrete wall to pass him. "You got a plan for this guy?" she said.

"Uh, hit him as hard as I can?" replied Tony. "That usually works."

The green and black clad figure veered around the corner into a concrete chamber. Gogo reached him first, yellow disk launching from her forearm and careening towards the man's head.

It passed right through him.

With a dull thunk, the disk crashed into one of the room's many pillars and clattered to the ground. The man turned towards the pair, flickering slightly as a sick grin twisted across his pale face. Dark laughter echoed through the chamber; golden-green light flashed around them, and dozens of other shimmering Loki apparitions began to materialize, all grinning and aiming their spears directly at their chests.

Tony swore loudly. "So…new plan?"

o-o

"Uh, guys?" Wasabi's question crackled through the comlink, punctuated by a loud yelp. "Are you seeing this?"

"A dozen copies of a homicidal maniac trying to kill us all at once?" Tony replied dryly. A loud boom thundered in the background, followed by a faint clanking sound. "Yeah, I'm seeing this."

Honey ducked behind a concrete pillar, flinching as a blue energy beam rocketed past her. Across the large hangar, Baymax launched his rocket fist into the swarm of Loki clones, while Steve deflected a series of energy blasts with his shield, the blue beams ricocheting back and dissipating the clones with flickers of blue and green light.

Panting, Steve rolled behind the pillar beside hers. "What's happening?" he asked, gesturing at the multiple clones peppered throughout the room. "Do you know how he's doing this?"

Honey shook her head. "I've never seen anything like this before," she confessed. "I mean, I've seen holograms before, but never any that have the capacity for concussive force." Her eyes darted to Baymax as the robot benignly called out karate moves, blocking several energy beams from their hiding spot. "We need to get out of here."

Steven nodded. "I saw a doorway on the right side of the hangar," he said.

A thin smile spread across Honey's face. "And I've got just the thing to clear the way." Carefully, she tapped a few choice buttons on the side of her purse before ejecting a translucent orange chemical ball from the side. "Baymax, thrusters, now!"

The hulking red robot immediately launched into the air, hovering above the mass of flickering green and gold light. Honey hurled the ball at the center of the room; the chemicals burst in a shower of orange and pink. A viscous orange gel began seeping beneath the mass of clones, and as it traveled, the golden light of the illusions began to waver, before each clone was sucked under the gel like a cobweb into a vacuum.

Honey grinned. "Endothermic gel," she explained proudly. "It absorbs high concentrations of energy from the surrounding environment. I'd been meaning to test that one for a while now."

Baymax landed beside the pair with a soft clunk. "Thank you for the warning, Honey Lemon," said the robot. "That was…sick." Upon seeing Steve's moderately confused expression, Baymax tilted his head. "Do not worry, Captain. It is just an expression."

Steve let out a small, tired laugh and gestured towards the door. "We should get out of here before more of those...copy-things return."

Baymax amiably shuffled out from behind the pillar, then paused. "There is still one left."

Honey and Steve paused, their eyes trained on the lone figure standing on the other side of the hangar. The air around him shimmered, and his black leather garments were suddenly overlaid with golden armor, an imposing horned helmet materializing on his head. With a vicious snarl, the man slammed the end of his staff into the gel—the orange surface turned icy blue, and shards of chemicals exploded outwards.

"Uh, guys?" said Honey. "I don't think that one's a clone."

o-o

"Quick—in here!"

Wasabi stumbled after Fred, leaning heavily on the thick blue arm of his friend's suit. One hand was wrapped around the fresh scorch mark seared into his green armor. "You know," he wheezed, "for a bunch of holograms, they really pack a punch."

Fred yanked him forward, using his free arm to slam a thick steel door shut behind them. "Are you alright, man?" He flipped his suit's three-eyed head back, genuine concern etched across his face. "I think I got a first-aid kit stored in the suit's butt somewhere…"

"No, no, it's fine. I'm good." Wasabi leaned against the wall, his shaky breath swirling dust particles in the dim light. "Where—Where are we?"

His question hung emptily in the cavernous space. Large stone arches raced across the room's ceiling, which appeared almost sickly green in the light. Old cabinets and tables were shoved against the damp concrete walls, and pipes and wires hung broken in the corners. Yet, despite the old, dilapidated appearance, the room was cluttered with modern technology, all laying eerily silent beneath haphazard plastic tarps. At the center of the room sat a plexiglass cube, the half-finished remains of a strange circular metal harness left inside.

Fred carefully picked up the edge of a translucent tarp. "I dunno, man," he said, peering under the plastic. "Looks like some sort of lab...place. Wonder what they were working on."

Wasabi limped towards the plexiglass cube, eyes fixed on the empty cube-shaped space in the middle of the metal circle. "That—That's an energy harness," he realized. "This was where they were working on the Tesseract!"

"Really?" said Fred, holding up a tablet. "Because this says they were working on some sort of...magnetic stabilizing device…"

An explosion suddenly rumbled in the distance. Some small pebbles broke loose from the ceiling, clattering down on the equipment with tinny thunks. A metal crate on top of a cabinet fell onto an adjacent table with a loud clang.

Something beneath the table whimpered.

"Uh, what was that?" whispered Fred, pulling the suit's three-eyed head back over his face.

"I'm...not sure," said Wasabi. Biting back a hiss of pain, he pulled the hand from his side and ignited both his plasma blades.

"Oh oh! Maybe it's Loki, but he's been shrunk down due to some magic spell, and that's why he's protecting himself with that army of cl—"

"Dude, shut up."

The pair edged towards the sound, pushing aside a tower of crates. Beneath the table lay a fourteen-year-old boy in a battered and scorched blue hoodie, messy black hair sticking out in all directions and wide brown eyes staring earnestly up at them.

"Hiro?"

o-o

"My, what have we here?" sneered Loki. "The chemist, the automaton, and the soldier. Quite a magnificent gathering, if I do say so myself."

Steve readied his shield. "Get back, you two," he commanded, casting a quick glance at Honey and Baymax.

Loki laughed. "You know, I really should be thanking you," he said. "Your little friend has been immeasurably helpful to my operation."

Honey's jaw tensed. "What have you done with Hiro?"

"Wouldn't you like to know?" replied the god with a grin.

Steve growled. "Enough with the games, Loki," he snapped. "What do you want with the Cube?"

Loki's smile twisted further upwards, baring his teeth. "I want a throne, Captain," he hissed. "And for the people of Earth to kneel before it."

"Funny you say that," said Steve, striding forward. "Because the last time I was in Germany with a guy set on world domination, we didn't get along."

The captain launched at Loki, slamming his shield against the blade of the god's staff with a metallic clang. With a snarl, the god easily kicked his shield away; his sceptre rammed into Steve's head, sending him sprawling. "Captain!" Honey yelled, fingers flying across her chemical purse. Quickly, she hurled the resulting pink ball towards Loki—he flicked it aside, and the sticky pink goo exploded on Honey's hand instead, pinning her against a concrete pillar.

Baymax benignly waddled over. "Do you need help?" he asked, easily ducking to avoid a wayward blast from Loki's staff.

"I'm fine," snapped Honey. With a few more buttons, another ball popped out of her purse, and she hastily applied the antidote to her hand. "We just need to—"

An explosion rocked the room, and Honey tumbled into Baymax.

"What was that?" she asked. Even Steve and Loki looked momentarily confused in the midst of their fight.

Baymax tilted his head pensively, then waddled over to a nearby pillar. "This is the source of the explosive energy," he intoned, holding out a blue shard. Behind him, Loki had thrown Steve across the room. "It has a 75% match to the—"

"—the Tesseract energy," Honey finished. She gently took the shard from Baymax's glove. "My endothermic gel from earlier," she realized. "This must have absorbed the energy from Loki's staff and—"

The shard sparked in her hand, and Honey dropped it with a yelp. All along the perimeter of the room, dozens more blue shards embedded in the walls crackled with energy.

Baymax blinked. "Oh no."

o-o

"Guys, we found him! We found Hiro!"

Gogo froze. "Wait, what?" she hissed into her comlink. With the sudden disappearance of the Loki clones, she and Tony had taken to exploring more of the base. "Wasabi, where are you? Is he hurt?"

"He looks pretty shaken up," replied Fred. "And there's like, a big cut on his arm, but it looks like it's already healed up. Wasabi took a huge blast to the chest, though."

"Not now, Fred!"

"Sorry!"

Gogo shook her head. "Where are you guys?" she reiterated, clicking down her visor.

"We're in some sort of...experimental laboratory," replied Wasabi. "We've looked all over the room, though. No Cube."

"That's fine," said Gogo. "We'll keep looking later. Right now, we need—"

The entire base shuddered violently, tossing Gogo and Tony to the ground. Concrete rained from the ceiling, and a chain of muffled explosions echoed throughout the halls.

"What the hell was that?" asked Tony.

Gogo pressed her hand to her ear. "Hey, is everyone okay?"

"We're good!" replied Fred. Her comlink popped with static. "That blast took out an entire wall though. Pretty sick."

"Honey? Captain Rogers?"

More static. "We're fine," Steve's voice rattled through the earpiece. "But we lost Loki. Guy leveled the hangar on us."

Tony scowled. "So we've got no Cube, and no Loki. Perfect."

Natasha's voice suddenly burst through their comlinks. "There's an unidentified aircraft leaving the base."

"Ground it," snapped Tony.

"No!" countered Steve. "If we shoot it, we could kill him. We need Loki alive to find the Cube."

"Well, I didn't ask her to blow up the damn thing, did I?"

Their ears rang with gunshots, followed by another blast and the distant blaring of several alarms. "Quinjet's been hit," said Natasha. "I can't pursue."

Tony swore loudly.

"Wait," said Honey, "Baymax, you scanned him, right?"

"Yes," replied the robot. "I am programmed to assess everyone's health care needs." A pause. "His body temperature is very below average, at zero degrees Fahrenheit. His blood pressure—"

"Great," scoffed Tony. "If he ever stops in for a check-up, we'll know it's him."

"No, idiot," snapped Gogo. "Baymax's scanner can track any biosignature within a six-mile radius sphere. If they leave now, they should be able to catch up to Loki." She pressed her hand to her ear. "Honey, you know how to pilot Baymax, right?"

"Yes," the other woman replied. "I'll take Captain Rogers with me. You make sure Hiro's safe."

o-o

Carefully, Honey applied an orange chemical ball to the bright pink dome encasing her, Steve, and Baymax. "I'm surprised that held against the explosion," said Steve, curiously watching the orange substance dissolve the chemical shield.

"It's a…formula I've been working on," replied Honey. She smiled tiredly. "Glad to know it works, though."

Steve frowned. "Are you sure you're alright?" he asked, picking his way through the rubble of the hangar. "You don't have to do this."

"The captain is right," intoned Baymax. "I am detecting several symptoms of fatigue, indicating that you should rest."

Honey shook her head. "You heard Gogo," she replied, clambering onto Baymax's back. "We need to leave now if we want any chance of catching Loki. I'll be fine."

Steve opened his mouth to protest, then decided against it. Hesitantly, he followed Honey and climbed on Baymax, gripping the edge of the robot's red armor to steady himself. "So, how exactly does this work?"

Honey Lemon smiled. "You might want to hold on tight, Captain," she said. "Baymax, full thrust!"

o-o

Thank you for reading! I've got some interesting things planned in the future, so stay tuned! (And, as always, please leave a review if you have the time. I really appreciate hearing all your reactions as readers.)