DISCLAIMER: I do not own Percy Jackson/Heroes of Olympus, all rights to Rick Riordan! I also don't own The Avengers either, so rights go to Marvel or whatever.

Connor grabbed Percy's arm and yanked him into an alcove where the lightbulb had gone out. Neither of them breathed as a squad of soldiers jogged past them. Percy exhaled, peeking around the corner.
"Thanks, Connor. That was a close one."

The alarm was blaring loudly, and faint red lights blinked farther down the corridor. Percy knew something was up. He and Connor certainly hadn't set it off. He hoped Annabeth and Travis were okay.
"You should be more careful," the son of Hermes replied, moving back down the hallway. Percy could tell the other boy was trying not to let the siren make him nervous.

Percy knew that if it hadn't been for Connor, he'd have been caught at least three times by now, and they'd only been inside the facility for ten minutes. Thankfully, Connor's hacking and thieving skills had paid off. They'd gotten inside without setting off any alarms. The kid was seriously sneaky.

They stayed close to the walls, Connor going first to keep a sharp eye out for good hiding places and the like, just in case they were suddenly caught. Percy guarded their rear, his hand nervously fidgeting with his pen—even though he was very well aware of the fact it couldn't harm mortals.

They reached an intersection, and Percy caught sight of a sign on the wall. He nudged Connor's elbow. "Look," he whispered.

Connor glanced up at it.

Holding cells 100-240. An arrow pointed left. 241-430 ; another arrow pointed right. Break room; a final arrow pointing straight ahead, further down the hall.

Connor started forward, moving towards the break room, but Percy grabbed his elbow.

"Connor," he hissed.

The son of Hermes was grinning. "Just teasing, Percy." He paused, looking down the hall in both directions. "We should split up. You go one way, I'll go the other."

Percy hesitated. "I don't know…it might be best if we stay together. What if something happens?"

Connor seemed to think for a minute, then shrugged. "Think about it. You've got your sword—how are they supposed to know it can't hurt them?—and we're both pretty good at hand-to-hand combat. I've got the advantage, what with all my practice getting away from the Aphrodite cabin."

Percy rolled his eyes, remembering the prank the Stolls had pulled on the Aphrodite cabin just before they'd left. Let's just say they weren't exactly happy campers when they woke up with green hair.

"Fine."

"Which way do you want, left or right?" Connor asked, evaluating both sides.

"I'll take right. You go left." Percy vaguely realized that it was quiet again. He hoped it had just been a false alarm.

"Got it," Connor Stoll said before creeping off towards holding cells 100-240.

Percy wasn't sure where cells 1-99 were. Maybe they started at 100 and counted up? It seemed unlikely that they would have at least 330 jails here. Percy shrugged. Maybe they had a lot of enemies. He could believe that.

He just hoped Nico was in one of those 330.

An hour later, Percy was really starting to get frustrated. He was currently peeking inside cell 420. Nobody. That seemed to be the thing here, having almost five hundred prisons and only ten with actual enemies in them. Cell 425 held a scrawny little guy with balding hair. Percy backed away when he received a nasty snarl from the man and foam started to drip from his mouth.

The son of Poseidon shuddered, moving to look in the next prison. Cell 428. A set of metal double doors with a huge padlock and coded sound lock protected it from intruders.

Nico has to be in here, he thought.

He glanced over his shoulder and set his hand over the padlock, concentrating hard. He felt that familiar tug in his gut and opened his sea green eyes to watch as spindles of water trailed across the walls and ceiling, racing down his fingertips and splashing silently against the lock. Another stream of liquid crept over to the sound lock, sending it into a frenzy of sizzling and sparking. Percy stepped back as the padlock snapped open and something in the doors clicked. Percy hoped that, since there was a lock on the door, no one would be inside except for Nico. Unfortunately, he figured SHIELD had some way to get out from the inside despite the padlock.

Making sure Riptide was still in his pocket, he shoved the heavy double doors open.

Annabeth Chase ran down the hallway, sirens blaring. She had no idea where Travis was, but she prayed to Athena that he was okay. She would never forgive herself if he didn't make it out of here.

Her blond ponytail whipped her face as she spun around. A row of guards was shouting at her, demanding she stop and surrender. She took off down the shiny metal corridor again, her breaths heavy, tennis shoes tapping against the floor. She caught sight of an open door and lunged through it into the darkness beyond.

It looked like a conference room, with a long mahogany table down the middle and cushioned chairs placed along it. Large windows spanned the length of the far wall, making her awestruck at the cityscape below her. She snapped out of it in a millisecond and dived under the table. The agents ran past the door, and one of them peeked in. He shined his flashlight inside, then jogged on.

Annabeth stayed put for a 10 count, then stood and peered out the door. The hall was empty. She breathed a sigh of relief and leaned against the doorframe, still keeping a careful eye out for soldiers. She felt bad for leaving Travis, even though, technically, they'd been separated due to no fault of her own.

Their mission: to get to SHIELD's control room and kill whatever locks they had on the prison doors. Knowing full well that that would set loose all kinds of nasty criminals—some of them no more a criminal than Nico—Annabeth, Travis, Percy, and Connor had brought something to protect them.

Annabeth reached in the pocket of her jeans and pulled out the thin glass vial. Grey-white mist swirled inside it, and Annabeth could almost hear it screaming to get free. It was legitimate Mist, the stuff in the bottle. The daughter of Athena had no idea how Hazel had obtained it, but she knew it wouldn't stay captured in the glass for long. They needed to hurry. The Mist would only hide them from supernatural beings, since they figured most of SHIELD's enemies weren't human. Annabeth only wished it would hide them from everyone's eyes.

She diverted her train of thought back to her mission. Once they freed Nico, hopefully Percy and Connor would have reached him in time to get him back to the roof and the hell out of this place. They'd figured he probably wouldn't be in good shape to shadow-travel. Then Annabeth and Connor would get to the east wing's third floor fire escape exit, where two pegasi would be waiting to get them out of there.

If things had gone to plan, they would have been able to escape SHIELD headquarters with Nico and never come back. Maybe then the government organization would have realized how dangerous demigods were and back off. Of course, things didn't go to plan and Connor had accidentally set off an alarm. Now soldiers had the place covered like a knee-high sock.

This was supposed to be a stealth mission, Annabeth thought to herself as she left the safety of the dark room.

"Hello Gentlemen." Percy Jackson strode inside the room with metal walls, a control panel stationed before a catwalk that led to a circular prison cell. The walls were made of glass. "Oh, sorry," the demigod said when he spotted the young lady scientist. "Ladies and Gentlemen."

"How did you get in here?" Agent Fitz demanded, rising quickly.

"Oh, you know. A little bit of this, a little bit of that. But I mainly just did this." Without further warning, Percy thrust out his hand, swirling a hurricane around him. None of the people in the cell had noticed the pool of water that had followed Percy through the doors. Honestly, the son of Poseidon had just made a lucky guess when he tried to raise that hurricane. It would've been pretty awkward if it hadn't worked.

He charged toward the cell door, sending the lock into a fizzling frenzy when it came in contact with the water. Percy yanked the door open, Riptide in his hand.

"Now, I suggest unless you're feeling dehydrated today, you step away from him and get on the ground." Percy did not like Nico's condition. He looked absolutely exhausted, his arm was swathed in creamy white bandages splotched with crimson, and he was shaking. From cold or anger, he couldn't tell.
The son of Poseidon spotted Agent Coulson reaching slowly toward the pin on his suit, obviously trying to call for help. He blasted him with a wall of water and the agent slammed into the glass wall before falling unconscious on the floor.

"Next?"

The scientists looked thoroughly scared and intrigued at the same time. He didn't miss the fact that one of them was scribbling furiously on his paper.

"Drop it," Percy snarled. No one was going to take notes on him like a freaking experiment. When the young man didn't comply, Percy pinned them to the wall with a surge of water and let it splash around them as their eyes fluttered closed. Thankfully, that was all the demigod was able to pull to the surface, so it was good all three agents were out cold. He dropped the remains of his mini hurricane and stepped towards Nico, offering him his hand. When Nico ignored it and stood, nodding his thanks, Percy remembered why he looked so worn out.

"You okay?"

The son of Hades nodded. "We need to get out of here. Did anyone else come with you?"

Percy nodded. "Yeah, the Stolls and Annabeth. I can send Connor an Iris-message real quick. Annabeth and Travis will meet us out there when they've finished their job. Be careful when we leave, because they shut down the locks on every cell out there. All kinds of guards and nasties will be wandering around."

Nico nodded and started toward the door.

"Wait, Nico," Percy said, grabbing his good arm to stop him. Nico shook himself free abruptly. "I need to know." He glanced past Nico toward the agents, who still appeared to be immobilized. "Where have you been going? You can't hide it, Nico. It's obvious you've been shadow-traveling somewhere recently. A lot."

Nico bit his lip. "SHIELD is planning something, Percy. I've suspected it for a while now. They've got some kind of weapon, this thing they call a—"

"Duck!" The son of Hades fell to the floor, not questioning Percy's urgent order. Unfortunately, the son of Poseidon was a split second too slow, and Agent Coulson's bullet grazed the demigod's left side. He hissed in pain and fell to one knee, quickly rolling out of the way as another shot was fired. Then Nico was on top of him and Coulson was knocked out again by the butt of his own gun.

"Thanks, man," Percy said, standing and clutching his side with his left hand, Riptide still in his right. Blood seeped through his fingers, but the demigod ignored it. He capped his sword and tossed Nico a vial of Mist. "Here, take this. It'll hide us from any non-human guys out there. I mean, since SHIELD seems like the kind of people who capture aliens a lot."

"Good idea," Nico said. "You okay?"

Percy laughed abruptly, remembering how he had spoken those same words just minutes ago. Ignoring the shooting pain in his side and the dizziness quickly assaulting him, he replied, "Yeah, let's go."

Okay, here you go. I thought I'd give you two chapters this time :D

Arrow :D