AN: Well, here's my cheap excuse to write another chapter on my beloved little Marine squad and a crossover fic at the same time. I guess it's only right for me to state the obvious legal stuff like I don't own Halo, Bioshock, or any of their associated properties. Enjoy!

"I am Andrew Ryan and I am here to ask you a question:
Is a man not entitled to the sweat of his own brow?

No, says the man in Washington. It belongs to the poor.
No, says the man in the Vatican. It belongs to God.
No, says the man in Moscow. It belongs to everyone.

I rejected those answers. Instead, I chose something
different. I chose the impossible. I chose…

Rapture."

—Andrew Ryan

Chapter 1: Under the Sea

Hampton Roads Naval Base, Virginia

Sensor Officer Paul McCullen rubbed his eyes to make sure they hadn't fallen out yet. Since the end of war, many of the posts in the Hampton Roads Naval Base were empty due to casualties and transfers to other bases to fill in personnel shortages. As a result, the remaining staff had to work extra hours in order to keep the facilities running at optimum efficiency. Currently Paul was sitting at a dark console listening for any anomalous signals coming out of Atlantic Ocean So far, the screen was dark and his headphones were silent. Paul then glanced across the room to see his fellow victim Rick. Rick was supposed to be keeping an eye on the sensor screens to make sure the airspace around the East Coast and the Atlantic Ocean were clear of hostiles. However, Paul could see that Rick was clearly not doing his job, as he was sitting face down on his screen, snoring like a dying elephant.

"Yo Rick! Wake up you lazy bum!" Paul shoved Rick roughly.

"What?" Rick yawned and rubbed the sleep out of his eyes. "What's wrong?"

"You!" Paul sighed. "I swear, you're supposed to be keeping an eye for any potential hostiles, not using the sensor screen as a pillow!"

"What's the point?" Rick leaned back in his seat. "That whole thing was months ago, and we haven't seen a single Covenant since then. They're probably all gone by now."

"Says you." Paul retorted. "There might be some remnants roaming around here somewhere, which is where you come in, since you're supposed to help find the bastards."

"Whatever." Rick rolled his eyes, bored. "It's just going to be the same old stuff as yesterday and the last month."

"Oh yeah?" Paul pointed at Rick's screen. "Then what the hell is that?"

"Huh?" Rick glanced at his screen and noticed a small, blinking dot on the screen, signifying an anomalous signal being picked up. "Oh shit!"

Paul leapt back to his station and pulled his earphones back on. He rapidly hit a few switches and buttons to try and tap the signal in that location. "Do you have a lock on the origin of the broadcast?"

"Uhhhh, yeah." Rick glanced at his screen. "It's coming from the Atlantic Ocean."

"What, over it? Some kind of ship?"

"No…" Rick frowned. "This can't be right. The screen's saying the origin is coming from under the ocean."

"That's not possible." Paul gaped. Suddenly, a burst of static revealed that he had finally tapped into the anomalous signal. He strained his ears to try and hear something, but the line was quiet except for random bursts of static. "I don't get it."

"Me neither." Rick shook his head. "I've double checked the sensors, and there's nothing wrong with them. Whatever is down there is definitely there."

"Shit." Paul muttered.

"What do we do?"

"What do we do? We report this." Paul picked up the nearby phone.

FLEETCOM Temporary Headquarters

Location: CLASSIFIED

"General Black." The secretary's soothing voice said over the intercom. "Please report to briefing room A. Priority level Obsidian."

General Marcus Black sighed and set down his papers. Black had never dreamed of ever getting a post in FLEETCOM, but with the heavy casualties from the Human/Covenant War, officers were in very high demand. Black had been stuck fighting a contingent of Covenant on a series of asteroid mines when word from Earth finally reached his location. The message he received informed him that the war was officially over and that he was to return to Earth immediately. The moment he returned, Black was immediately whisked away to FLEETCOM's temporary headquarters to work on the rebuilding of the UNSC's depleted armed forces. While Black enjoyed powers and oversight not normally granted to men of his standing, it certainly didn't mean he had less work to do. He had to spend countless hours reading over reports to make sure the UNSC's reconstruction efforts were on schedule and under budget.

However, Black was not alone. When he entered the briefing room, he saw various Admirals, Generals, and even some Colonels and Majors sitting at the briefing table. Black hadn't had the time to familiarize himself with the rest of the FLEETCOM staff, but the one face he certainly did recognize was Fleet Admiral Lord Terrence Hood, who was sitting at the head of the table.

"I'm glad you could make it all here." Hood addressed the gathered officers. "I'm sorry for the abruptness of this meeting, but the matter is urgent."

Hood then nodded to the side, prompting Black to look in that direction. Standing to Hood's left was a man wearing an ONI service uniform. Black had honestly not noticed the spook when he first entered the room, but wasn't surprised. A spy that could draw attention to himself would not be a very good one.

"Well, since it's safe to assume none of you know about what we are going to discuss, I'm going to have a request a level six information lockdown on this room." The spook glanced at Hood, who nodded and pressed several keys at his position at the table.

The special aspect of this briefing room was that it was designed to be completely impenetrable to surveillance and eavesdropping devices. The room was in the interior of the base and suspended over the ground by wires and shock absorbing springs and the interior walls were designed to be echo-proof so that the vibrations of their speech could not be detected from the outside. The interior walls were also laced with electrified copper wire and countless electronic jammers to disrupt possible transmitters, and many of the freshly minted FLEETCOM officers learned the hard way not to bring electronics of any kind into the briefing room, as a small EMP pulse generator was installed to fry any potential recording devices.

Satisfied that the proper precautions were set in place, the spook finally spoke again. "Now I suppose it's only proper to give you all some background information. Are any of you familiar with Ryan Industries?"

There was a brief moment of confused whispers and glances. Ryan Industries had once been a bustling and flourishing technology corporation, headed by the rather eccentric visionary Andrew Ryan. Roughly two decades ago, while the Human/Covenant War was still a distant Outer Colony affair, Ryan took all of his company's assets and completely disappeared without a trace. Since then, there was much speculation on where Ryan went and what he did with all of that wealth.

"I'll take that as a yes." The spook continued and activated a holographic display, which flitted between various pictures of Ryan Industries locations, staff, as well as Ryan himself. "As you know, Ryan Industries was one of the biggest tech companies and military contractors and was headed by a man named Andrew Ryan. However, what most of you may not know is that Ryan's business was plagued various complications, such as industrial espionage, numerous anti-trust and monopoly cases, lawsuits from disgruntled workers, and many more troubles. As we could see from the past, stuff like that was the death knell of any large company. The situation finally came all to a head when the stockholders considered ousting Ryan as CEO and President of the company."

"Pardon me." An Admiral raised his hand. "We have some very pressing problems now. Why are we concerning ourselves with a company that went under twenty years ago?"

"I'm getting to the point. Please be patient." The spook said rather harshly. "Anyways, it was at this point Ryan shut down Ryan Industries, took all of its assets including stocks, money reserves, equipment, and staff, and disappeared. Now, this was a huge scandal at the time since Ryan basically cheated his stockholders out of hundreds of billions of dollars. Of course, the Office of Naval Intelligence kept a close eye on the situation."

"Then why didn't you do anything about the situation?" Hood asked, just as surprised at this revelation as the rest of the officers in the room.

"We only had orders observe, not to interfere." The spook replied simply. "Back to the point, the agents assigned to the mission at the time kept track of what the stolen money was being used for, all under fake names and known fronts for Ryan Industries. Based on the equipment being bought and the expertise being recruited, we suspected that Ryan was planning to build a new base of operations. However, we were never able to find out where, until today that is."

The spook then hit a key and the hologram shifted into a holographic representation of Earth. The display then zoomed in until it focused over a blinking dot in the middle of the Atlantic Ocean.

"Just two days ago, a listening post detected an anomalous transmission in this area. The frequency doesn't match any known UNSC frequency, secret or not, and as far as ONI was concerned, there was nothing there." The spook then pointed at the blinking dot. "However, recent events suggest otherwise. Based on evidence at the time and some scrupulous investigation, we at the Office of Naval Intelligence have come to believe that this is where Ryan has been hiding these past few decades."

"Is there any way to confirm this?" Black asked suspiciously. There had been many claims as to where Ryan could have gone, and the rumors were just as prevalent and farfetched as the lost city of Atlantis or the biblical paradise Eden.

"No, which is why ONI is bringing this to your attention." The spook replied. "It's imperative that a discovery like this be kept top secret, because there's no telling what the public backlash might result in, especially at a time where the UNSC is weak. We're asking that we take a small unit of your most trusted and loyal Marines in order to confirm this."

Most of the officers looked around nervously. None of them were willing to hand over, and in turn potentially sacrifice, any of their units to some half-baked ONI operation based on a similarly half-baked conspiracy theory about a rich runaway industrialist. They all started shaking their heads and making excuses on how they were short handed and couldn't spare any manpower. Black shook his head in disgust. Nobody here was brave enough to stand up and commit. That was probably why none of them were in FLEETCOM in the first place.

Sitting next to him, Black noticed that it was Major Mackenzie. Black remembered him back from that Christmas operation a few years back, and remembered that he ran a tight and dependable unit. The only difference Black could see was that Mackenzie was sporting the rank insignia of a colonel.

"Can you believe the nerve of these so-called officers?" Black whispered to Mackenzie. "A pressing mission pops up and they all start dragging their feet."

"To be honest, General, I can sympathize." Mackenzie replied. "There've been a lot of Marines who've felt that they been used by ONI and tossed aside when everything was finished. Given the recent events in the war, I'm sure that idea is fresh in all of their minds."

"I know you run a tight unit." Black said. "I remember them back from Tau Serra, some of the toughest Marines out there, in my opinion."

"It's nice to know that we're appreciated, General." Mackenzie smiled. "I'm sure I can spare some personnel. But then again, that's your call, since you're technically my superior officer."

"Really? I must've missed that memo." Black grumbled. He still hadn't even gotten through a quarter of his administrative workload. "Alright, I'll handle this then."

General Black then stood up to address the crowd. The rest of the officers quieted down and the spook gave an amused look. Hood then said, "General Black, do you have anything to say?"

"I'm volunteering my Marines to participate in this mission." Black announced proudly. He could notice Hood nodding in approval and the spook smiling.

"Excellent." The spook clapped his hands together. "Well then, I believe that concludes this meeting. General, if you could join me and Admiral Hood for further discussion that would be wonderful. The rest of you are free to leave, and remember, that level six information lockdown means that not a word of this conversation is to be uttered outside this room."

The spook waited for the rest of the officers to file out of the room. They all left except for Colonel Mackenzie.

"Don't worry about him." Black preempted the spook. "He's my subordinate."

"I see." The spook nodded.

"We'll take care of the technicalities later." Hood said. "Continue."

"Right, well, I must ask that you provide nothing but the best you can offer." The spook said. "I of course have no jurisdiction over your choice of unit, but that's what my superior recommends."

"I'll keep that in mind." Black said. "By the way, I don't recall you ever introducing yourself."

"General!" The spook looked genuinely hurt. "After all these years, you can remember Colonel Mackenzie here clearly, but not me? Don't you remember that somewhat obnoxious and troublesome ONI operative on that same operation?"

Suddenly, the realization hit Black like a MAC round. "Hubbard!" He yelled in surprise.

"You do remember!" Hubbard grinned. "How does it feel to be working together again after all these years?"

Black snuck a glance over to Mackenzie and Hood. Mackenzie rolled his eyes and shrugged while Hood merely grinned in amusement.

"Well then, now that we've all introduced ourselves, let's get started." Hubbard pressed another key. "We've already taken care of the logistics of the operation…"

Edwards Air Force Base, California

"So? How was the trip?" Karla asked as she watched the construction crews working.

"Nothing special, Major." Tarin shrugged as she stood alongside her commanding officer.

"Come on, Captain." Karla grinned. "You're a girl of many talents, and I know for a fact lying isn't one of them."

"Okay," Tarin sighed, "we made out."

"I fucking called it." Karla smiled and clapped her hands together. "Thanks to you, I've got two months of extra wages to waste."

"Wait…" Tarin gaped. "You mean you were actually making bets on me and Williams?"

"Well… yeah." Karla smiled in amusement. "I don't get why you're so surprised. This is the Marine Corps, where everybody is concerned with everybody else's business, especially if they can make a buck off it. It happens all the time."

"And you condone it?"

"Not like I can stop them." Karla shrugged. "Besides, as the commanding officer, I'm usually above that sort of stuff, unless somebody I don't particularly like gets involved. Poor Armbruster is not going to be happy to know he lost what he thought was a sure thing."

"I can't believe this." Tarin shook her head.

"You know what I can't believe? That people didn't even think you would hook up with Williams at all. Some of them even though that you swung the other way!"

"Please tell me you're kidding." Tarin buried her face in her palm in embarrassment.

"I can drive a Warthog and I can shoot a rifle, but I can't kid." Karla said with a serious tone, but eventually cracked a smile. "Stupid bets aside, what'd you do?"

"Like I said, we made out once… or twice."

"Did you…?"

"No!" Tarin's face reddened. "Can we change the subject, please?"

"I'm just messing with you." Karla smiled. "Anyways, better go pack your things. Full combat load."

"Something happening?"

"The Colonel won't say exactly what it is, but it's definitely something big." Karla said simply. "Get your company organized, and tell them we're going in light."

"I'll get right to it, Major." Tarin nodded.

Edwards Air Force Base Firing Range

Since the base was still under construction, the building of a firing range was still fairly low on the priority list. However, for those Marines who wanted to keep their marksmanship skills sharp, waste some time, or blow off some steam, the ramshackle, temporary range was good enough for them. The firing range was simply a patch of salt flat a few hundred meters in length with a large dirt mound at the end to catch stray bullets. At the other end, there were mats, foxholes, and a makeshift wooden rail to accommodate various firing stances, and motorized pop-up targets made up the majority of the "enemies" on range.

Sam scored another headshot on a supposed "enemy", and smiled as the target flipped over to signify it had taken a hit. So far, she had a hundred percent accuracy rating, and all she was doing was sighting her new rifle. Unfortunately, she couldn't keep the Earthshaker, or at least not in any practical sense. The ammunition it used as nonstandard and therefore difficult to get from official Marine channels. However, every cloud had its silver lining, and Sam's share was a brand new SRS99D-S2 AM sniper rifle. Karla had even made sure that the rifle was built so that if fit perfectly with Sam's size and build, resulting in a more lethal soldier and weapon. Sam saw the faint smoke trail of her next round spear into the next target, knocking the steel dummy over with a new dent in its "head".

"Well, you definitely haven't lost any of your sharp sight, that's for sure." Leo said as he watched Sam's performance through a scope. "That's eight for eight."

"I have to admit, it's a whole lot better than the old one." Sam smiled and ejected the magazine, making sure that there were no live rounds left in the weapon. "It's got a bit more kick to it, but other than that, I can put my faith in it."

"Glad to hear that you're so enthusiastic!" Paccone grinned as he stepped between the two Marines and hooked his arms around them. "Good to see morale is high, because we're moving out!"

"What? Already? I was under the impression what's left of the Covenant were running for the hills." Leo said curiously.

"Don't be silly!" Paccone slapped Leo on the back rather hard. "Marines didn't used to always bash in alien skulls. Back in the old days, they bashed in other people's skulls just as well!"

"So it's not Covvie related?" Sam raised an eyebrow.

"No idea." Paccone shrugged. "I was just told to tell you to pack up and get ready to ship out. Our pickup is coming first thing tomorrow morning."

Sam and Leo just looked at each other blankly. Theories about what they could possibly be tasked to do spawned in their heads, but both Marines kept their thoughts to themselves.

"Now if you excuse me, I've got an 'appointment' with your sister." Paccone let go of Sam and Leo and made his way to the firing range exit. "Part of the daily duties I have to fill out as a peacetime soldier."

Sam could only shudder at the thought of Paccone ever being her brother in law. It was quite possibly the most awkward and embarrassing situation she could ever think of being in, other than getting a plasma grenade stuck to your face, but that was a whole different story for another time.

"I sometimes wonder what they actually do when they're alone together." Sam shook her head sadly.

"You actually sound… mature." Leo said in mock astonishment. "Can this possibly mean you're taking something seriously?"

"Shut up." Sam shoved Leo lightly in the shoulder. "It's really rude to make fun of people like that."

"Right." Leo helped Sam pack up her rifle and latched the case closed before saying, "Are you really against Sarge hooking up with your sister that much?"

"Words cannot even begin to describe it." Sam sighed. "Think about it. Do you want see Sarge hanging out in your own house on an every day basis?"

"Point." Leo shuddered.

UNSC Frigate Miller

Currently holding station over the Atlantic Ocean

Two days later

Captain Rogers tapped his finger impatiently on the armrest of his chair as the Miller performed a deep penetrating sensor sweep of the Atlantic Ocean below. Scanning through ocean was often troublesome because of the sheer distance between the surface and seabed, as well as the presence of the huge amount of water in between. However, it wasn't the fact that sensor sweeping was a boring task that was irritating Rogers. It was the fact that he had his command of Freedom taken away and was transferred to this frigate. Truth be told, Rogers was never officially in command of the Freedom and was only put into that position due to the desperation of war. Plus, it was a prototype ship that was never designed for frontline combat in mind, and the whole ship had been taken to a classified shipyard for further study and testing.

However, Rogers should've considered the fact that he was even given command of a working ship a blessing. After the battle over Earth, the vast majority of the UNSC fleet was decimated. The only working ships so far were the few that survived the initial battle, the ones scattered in the colonies that weren't recalled to Earth, and the many that were hastily salvaged, repaired, or recommissioned. Miller was heavily damaged during the battle but managed to survive structurally intact. After a rigorous stay in an orbital dock, the Miller was ready to serve the UNSC again.

Finally, one thing that Rogers considered a mixed blessing was that Joshua had been carried over from the Freedom to the Miller as well. The ONI spooks wanted to purge all of the original crew from the ship, including the AIs. Doubtless they wanted a handpicked crew of their choosing that would follow their orders.

"How is the scan coming along, Joshua?" Rogers sighed.

"The scan is only seventy percent complete." Joshua chimed. "Please be patient while the program is running. Would you like to play a game to pass the time?"

"That's not necessary." Rogers waved off the request and turned to the Colonel and ONI spook standing behind him. "So what are we looking for again?"

"An underwater facility." The spook replied simply. "We lost track of it during the war and we simply want to confirm whether it's still intact or not."

Rogers doubted that the spook was telling the whole truth, but he was in no position to ask questions. "Joshua, are the DSTVs prepped?"

"They're being fueled as we speak, Captain."

As part of the operation, the Miller was also carrying two Deep Sea Transportation Vehicles. They were basically large submarines whose original purpose was to ferry workers to underwater mines or geothermal planets. One vehicle could carry up to twenty men and stay underwater for several days at depths of up to six hundred meters. These were the perfect vehicles to convey passengers to the underwater facility.

"Captain, the sensor sweep is complete, and I believe our scans found something." Joshua activated the holographic screen. "Our sensors have detected a structure covering several square miles, and it has all kinds of flat surfaces, straight edges, right angles, and other phenomena not commonly found in nature. I have a ninety nine percent certainty that whatever is down there is man made."

"Is that where the signal is originating from?" Ryan asked.

"We are well within the fifty mile margin of error. I am positive that this is where the signal is originating from."

"Alright." Rogers stood up. "Bring the ship down and land it in the water. Prep the DSTVs and the deployment hangar." He then turned to Colonel Mackenzie. "I trust that you can get your men in order, Colonel."

"Already on it."

Hangar Deck

Karla watched as forty Marines slowly piled into the two submarines sitting inside the hangar. Because of their limited logistics, the Marine force would have to be transported down to the underwater facility piecemeal. Williams and Tarin were taking the first platoon down to secure a landing zone for the rest of the reinforcement waves. Karla would follow on the second wave and reinforcements would slowly trickle down.

However, Karla had a very uneasy feeling, and it wasn't because of the gentle rocking of the waves hitting against the frigate. Everything about this mission had something that could go wrong. The submarines might suffer a mechanical failure and crash. They could run into some kind of defense system, or they could lose contact with the surface. Karla really didn't like the idea of being stranded hundreds of feet underwater all alone in an unknown environment. Karla took one more look down at the deck and managed to catch a glimpse of Sam and her squad boarding one of the subs. Karla quietly hoped that the submarines would get down safely, and exited hangar deck. Once the subs were loaded and sealed, the hangar would be flooded to allow the subs to exit.

DSTV One

Williams leaned back and closed his eyes, trying to not to think about the cramped space of the submarine or the hundreds of feet of water pressing down all over the sub. Tarin, however, didn't suffer from such phobias and kept an eye on the rest of the Marines inside the sub. Most of them were anxious for the ride to finish so that they could get out of the sub. It was no different than a tense Pelican ride, except at the first sign of structural failure, the sub and all of its occupants would instantly be crushed by the pressure of the ocean.

Tarin could now see why Williams was so nervous.

DSTV Two

"I'm not sure why you're brining your sniper rifle." Leo said, annoyed at how part of the rifle's bipod was stabbing into his side. "I don't think there's really enough space in an underwater facility to accommodate such a thing."

"You never know when you might need it." Sam said as she held the rifle close. "Besides, I just got this thing. No way I'm letting it out of my sight."

"Alright ladies and gentlemen, listen up!" Paccone yelled from his seat at the head of the sub. "We have no idea of what the condition of our LZ is, so I want you all on your toes! Weapons live and eyes open! If I catch any of you slacking, you'll the first out of the airlock!"

There was a cacophony of affirmations and laughter when Kumi glanced out of the viewport and gasped, "Holy hell!"

This prompted the rest of the Marines to try and get a look outside. What they saw was breathtaking.

Sam managed to turn around to look out of her viewport, and saw not just an underwater facility, but an underwater city. The massive steel structures jutting out of the sea bed reminded her of the mighty skyscrapers that dominated the skies at New Mombasa. However, building in open air was a relatively simple thing to do, but to have a city this size this deep underwater? It was something that didn't seem possible.

"What the hell is this place?" Leo gaped at the various colorful lights dotting the underwater city. "How could we have not known about something like this?"

"I think that's why we're here." Sam said, still marveling at the sheer novelty of an underwater city.

The submarine eventually reached the city itself and started to maneuver between the buildings, like a maze of artificial canyons. Sam could see signs, advertisements, and even the interiors of some of the buildings. She thought she could see movement in some of the windows and the glass tubes connecting individual buildings, but the sub was either too far or the view was too distorted for her to confirm. This continued for a few minutes before the submarine began to slow down.

"Alright." The helmsman's voice crackled over the intercom. "We've reached a suitable landing zone. We're extending the docking collar. Please refrain from opening the hatch until the light turns green. I don't want some idiot opening it prematurely and flooding the whole sub."

There was a dull thud as the docking collar made contact with the building they were stationed against. There was a faint hiss as the air pressure equalized and the hatch light turned green.

"All right, see you on the other side." Paccone said as he unsealed the hatch and exited the submarine.

What awaited him and the rest of the Marines on the other side would exceed their wildest imaginations… and fears.