Actions

Work Header

Living For Another Day

Summary:

The Master Chief, his AI Joyeuse, and pilot Esparza find themselves transported to a different time and universe, to an era where humanity faces yet another ancient evil that conspire behind the shadows. But this time, they won't have to fight alone.

[New chapter weekly/biweekly, depending on how busy I am.]

Chapter 1: Slipspace Rupture

Summary:

A mysterious vessel crashes on Eden Prime in a middle of Geth attack. Kaidan Alenko is sent to investigate the vessel.

Notes:

(See the end of the chapter for notes.)

Chapter Text

Lilliane Jane Shepard was just about to finish asking some questions to the one surviving Marine on Eden Prime she had just run into, Ashley Williams. She wanted to know whether or not there were any civilian survivors from the Geth attack on the colony. However, she was interrupted when suddenly her radio, and everyone else's, picked up a transmission.

“Mayday, mayday. This is UNSC Pelican Echo-216. We are experiencing catastrophic engine failure, post-slipspace transit failure, and losing altitude. Crashing on a potentially uncatalogued garden planet in UNSC sector grid 6QFJ17. Mayday, mayday. Request immediate extraction.”

Everyone looked at each other in confusion. Whoever spoke that emergency message speaks in perfect English, yet nobody has ever heard of this UNSC, or slipspace transit. Shepard thought to herself, could it be a Cerberus cell? 

However before she continued that train of thought, the emergency message transmissions were cut by Nihlus, his breathing sounds ragged as if he was injured.

"Spectre Nihlus to Fireteam Alpha, did you receive the emergency message as well?"

"Nihlus, this is Fireteam Alpha. Emergency message received. Over."

"Does humanity have an organization designated U.N.S.C.?", said Nihlus as he spelled each word individually. 

"Negative in the Alliance database, Nihlus. Possible unknown contact. We may be dealing with an unidentified vessel."

"Understood. Fireteam Alpha, split your formation. One operative will scout the unknown vessel's crash site and report on potential hostile activity. This is a First Contact scenario so observe protocol accordingly. The remainder will take point to secure the Prothean artifact. I am injured, and Spectre Saren is operating in this sector. Consider Saren hostile. He is collaborating with the Geth."

"Copy last, Nihlus. Confirming a hostile Spectre in the AO?"

"Affirmative."

"Kaidan, I need you to move to the designated coordinates and confirm the unknown vessel's crash site. Once secured, RV to our position. Ashley, you are with me. Move out.", she said.

Kaidan saluted and headed to the possible crash site of the unknown human vessel, leaving Shepard and Ashley to rendezvous with Spectre Nihlus. The commander wondered to herself if this day could get any more interesting.


“Chief, Chief, wake up!”

The faint shouting from Joyeuse woke the Master Chief up. Thankfully he wasn’t injured, but judging by the MJOLNIR-shaped dent around the Pelican, he had experienced another bumpy landing.

“Esparza is not responding and I can’t get a read on his life signs. Hurry, open the cockpit while I try to figure out where we landed.” The Spartan stood without saying a word of response to his AI companion, his eyes scanning for a first aid kit. Through the mess of thrown-around supplies, he spotted the red medical box, holding it in his left hand while he tried to open the Pelican door with his right hand.

While the sliding cockpit door was jammed, it only presented little resistance to the Spartan. Esparza sat unconscious on the pilot seat, his ragged uniform covered in blood.

“Chief, he needs a med-evac now, but we should have enough bio-foam to seal his wounds. I am trying to triangulate the nearest UNSC comm buoy to send–,” said Joyeuse as Chief carefully applied bio-foam to the pilot, his left hand spraying the wound while his right hand tried to pick any debris sticking to the pilot’s wounded body.

Silence filled the room after Joyeuse stopped talking. Chief didn’t ask why she stopped, even though he wanted to know, but he knew he needed to finish applying first aid to the pilot.

After he finished, Chief finally broke the silence.

“What is it?”

“I made a scan of the planet terrain before we crashed. The topography doesn’t match any catalogued garden world candidates. But based on my triangulations, we are on Reach. Or, where Reach was supposed to be.” Chief instinctively looked to his left at the broken Pelican window, trying to make out any landscapes of Reach he could identify. He couldn’t identify any of it, and the sky had a reddish hue that Reach never had.

“How…,” Chief looked back at Esparza, his visor betraying a look of concern. “...how is that even possible?”

“I don’t know.”

Chief looked down, his mind racing for a solution. “Any UNSC comm buoy we can reach out to?”

“None, however, in its place, I identified an unknown military comm buoy, belonging to a human military force called System Alliance. I sent an SOS transmission over any open radio channels, so maybe they could pick it up.”

Chief frowned behind his helmet; he didn’t know what the System Alliance was. They could be insurrection forces or some outer colony government that decided to break away from the UNSC. Joyeuse could tell that Chief disapproved of her decision.

“Chief, I know you disagree with me, but we had no other choice. I only identified the System Alliance comm buoys after you asked. Speaking of–,” Chief noticed a yellow diamond light up on the motion tracker on the bottom left of his VISR.

“Contact. Outside the Pelican. Huh, interesting.”

“How so?”

Joyeuse materialized on his left hand, nudging Chief to look at her, smiling and excited to inform him of whatever she had discovered. Chief kneels down and raised his left hand in response.

“I hacked into the personal device of an unknown contact outside. Chief, it’s a human!” Chief leaned closer to the joyful AI. But even without that, she could tell from the Spartan’s brain reaction that he was inquisitive about it.

“I know you are going to ask how that is possible. We are on an unknown planet where Reach is supposed to be, yet there is a human. My best theory is that the slipspace anomaly we encountered when we tried to run away from the Reckoner led us back in time to another universe.”

Joyeuse materialized a bunch of holographic windows around her, her hands held behind her back while her body swung excitedly, “And I managed to download something called a ‘Codex’ from the unknown contact’s device. And according to the ‘Codex’, we are currently in the year 2183.”

Joyeuse showed Chief a map of UEG colonization during the year 2183, overlaid with the galactic map from this System Alliance, “On our Earth, we had barely managed to colonize the entire Solar System during this time period, and yet, wherever we are, humanity has colonized garden worlds as far as 40 light-years away from Earth.”

The Chief couldn’t help but be impressed. He wasn’t even born yet when humanity reached out to the stars, and yet here, they also expand beyond the solar system. However, one thing still nags the Spartan.

“This discrepancy leads to only one conclusion, Chief,” Joyeuse looked up at the Spartan, her joyful expression now slowly eroding to a somber one, hoping the Spartan would reach the conclusion by himself.

“We are far from home.”

Joyeuse nodded in silence, but Chief did not give her a response. Her expression turned into one of concern.

“Chief, I know what you are thinking. But Esparza needs medical attention, and the System Alliance could help us until he recovers. After that, you’ll do what you do best.”

“Improvise.”

Joyeuse flashed a smile, “Exactly,” she dematerialized from Chief’s hand. She knew now that the Spartan was determined to ask for help, even if it meant from a military force of humanity from another dimension.

“Let’s go Chief, we got some improv to do,”


Kaidan observed the crash site of the UNSC Pelican through the Omni-Tool’s camera function.. Judging by the looks of it, Kaidan thought it sort of made sense for it to be named a Pelican; after all, it has a profile that resembles a bird more than an airship. And judging by its size and the engine that was visible to him, it seemed to be a military shuttle aircraft the size of two Kodiaks stacked on top of one another.

However, he couldn’t help but find the whole thing odd. Not only did whoever spoke the SOS message speak perfect, honest-to-God, American English, but the inscriptions and logo visible amidst the scratch and burn marks were also in English. The UNSC insignia, or what Kaidan could make out from it, resembled the humanity military from old sci-fi vids he used to watch with his dad, as opposed to the sleek design of the System Alliance and other paramilitary groups like Cerberus.

Whatever this UNSC is, Kaidan thought they must be really serious about military doctrine, which could pose a threat to the System Alliance.

Kaidan took a scan of the crashed vessel for an eezo signature; oddly enough, he couldn’t find one. Kaidan ran the scan twice to confirm the readings, as he couldn’t believe it.

A space-faring military shuttle aircraft with no eezo. Kaidan thought to himself, wouldn’t a breakthrough like this, especially one that is done outside of the System Alliance’s influence, have caught the attention of AIS?

He quickly sent the readings and photos to both Anderson and Shepard. Whatever that just crashed on Eden Prime is something that is as odd as Geth leaving the Perseus Veil to attack the very colony too.

Minutes passed without a response from either Shepard or Anderson. Minutes passed and the Pelican was still unmoving, no doors opening. Kaidan started to worry that perhaps there were no survivors from the crash, as he tried to scan for life signatures and found none.

The silence was broken by Anderson, and Kaidan took a sigh of relief.

“Overwatch to Fireteam Alpha, make contact with the crash-site immediately following beacon extraction with Spectre Nihlus. ARCCOM has designated the recovery of survivors and unidentified human vessels as Priority One. The Citadel Council has been notified and agreed this is an Alliance-only affair.”

“Affirmative, Overwatch. Shepard to Alenko, is the crash-site secure of hostile elements?”

“No geth activity detected around the crash site. No one inside the crashed vessel have yet to emerge, currently in a holding position.”

“Copy. Alenko, remain in holding position until any survivors leave from the vessel.”

“Affirmative.”

“Fireteam Alpha to Overwatch, crash-site is secure and Alenko is holding position. What’s the play?.”, asked Shepard over the voice channel.

“Secure all recoverable personnel to Normandy and proceed to rendezvous with SSV Orizaba. Overwatch out.”

Kaidan raised his eyebrow in shock, however he heard loud hiss from the crashed Pelican which caused to be even more shocked. 

“Alenko to Overwatch, survivors are emerging from the crashed vessel,” said Kaidan as he watched the Pelican’s bay door slowly open, revealing what looked like a human in an armored suit. Kaidan could only make an educated guess on the man's height, but he had a feeling the armored man's towering height was not just the product of good genetics.

“It seems to be one…human?”, Kaidan continued. Both Shepard and Anderson could hear Kaidan’s hesitancy over the radio. 

“Copy last Alenko, are you not sure the survivors are human?”, asked Shepard. 

“Well it seems human or humanoid. Five fingers, human physiology, wearing an unidentified full body armor. However, from my estimation the survivor height is at 7 feet or higher.”, Kaidan replied.

“Overwatch to Alenko, could be someone from the free colonies wearing experimental tech. Keep your eyes peeled.”, commanded Anderson. 

Kaidan gave a short "roger" reply before he noticed that the unknown armored figure saw him. Or at least Kaidan thought the figure was staring at him; he couldn't really tell from the glaring gold-yellow visor, but he could feel it. His mind was racing on what to do. Should he ready his weapon, or should he raise his hand, signaling that he was friendly? The armored figure stood as imposing as a Krogan Warlord, and judging by the body armor plating, Kaidan thought it would also be as hard to take down as a Krogan Warlord. He decided to raise both of his hands in the air, hoping the armored figure understood.

"Friendly, friendly!" shouted Kaidan.

The armored figure just stared at him. Kaidan couldn’t tell whether or not the armored figure understood him, but he got their attention now. It’s now or never.

“Okay, I am going to slowly approach you to make contact. Do you understand?”, the armored figure nods. Kaidan slowly walked down the slope, hands up in the air, heading to the crash site.

The smell of smoke and burnt ashes filled the air, as Kaidan stood in front of the armored figure. His estimation was right; the armored figure was roughly 7 feet tall, and Kaidan needed to slightly look up to even talk to them. Now Kaidan just hoped he wouldn’t be smashed to pulp by it.

“Staff Lieutenant Kaidan Alenko of the Systems Alliance. Human. On behalf of the Systems Alliance, we received your distress call, and we come in peace. Can you identify yourself?”

The armored figure tilted their head down to stare at Kaidan directly in his eyes, or at least that’s what Kaidan thought.

“Master Chief Petty Officer Sierra-117 of the United Nations Space Command. Human,” replied the armored figure in a deep, gruff voice. Kaidan was relieved to hear that the armored figure was human and came from a semblance of a military background, but his identification confused him. For one, his name has a serial number, which could mean he is a clone; which would make this a Citadel problem, as the level of cloning and genetic engineering required to create a soldier like this Sierra-117 violates multiple Citadel Laws.

Two, which is something Kaidan was about to ask:

“We’ve never heard of any United Nations Space Command. Is it a new paramilitary branch of the free colonies?”

“The United Nations Space Command is the military, exploratory, and scientific agency of Earth and all of her colonies,” replied the armored figure.

“Okay Sierra, you lost me. The representative body of Earth and all human colonies in Citadel space is the System Alliance.”

The armored figure tilted its head slightly, either in confusion about his situation or the fact Kaidan just called him Sierra. Kaidan couldn’t tell. Silence fell between the two men, and Kaidan started to feel unease.

“I need to review the discrepancy later. Does the System Alliance have medical facilities nearby?”, asked the armored figure.

“There is, however, this colony is currently under attack. Is anyone in the vessel injured?”, replied Kaidan.

“One, a human, the pilot of this vessel. Internal bleeding has been stabilized with a first aid kit, but he needs immediate CASEVAC.”

“Any other survivors?”, Kaidan asked without hesitation. 

“Negative.”

“May I confirm the status?” The armored figure nods at Kaidan's question, stepping aside to allow him to enter the Pelican. Kaidan’s guess was right: it is a transport vessel, with five seats on each side and crates with the same UNSC insignia lying around in chaos. Kaidan reached the cockpit of the Pelican and found another human wearing what looked like a pilot uniform, stained with blood down from his abdomen and lying unconcious.

Kaidan checked the wound and found it had been sealed with unknown medical foam that had hardened, probably what the armored figure meant by a first aid kit. Kaidan made a mental note of how odd it was that they didn’t use medi-gel, as if they didn’t have access to it somehow.

Kaidan applies his supply of medi-gel to at least help with some of the recovery. However, reading the pilot's vital signs using his omni-tool didn’t paint a pretty picture.

“Shit,” Kaidan muttered to himself. The armored figure might be an unknown element, but they are still human after all, and humans who are trapped in an active invasion. Kaidan rushes out from the Pelican, making eye contact with the armored figure and simply nods. His omni-tool is ready to enable radio comms.

"Alenko to Fireteam Alpha. I have established contact with survivors from the unidentified craft. Confirmed survivors are human. Repeat, confirmed survivors are human. One subject is ambulatory, one requires immediate CASEVAC.", Kaidan’s comms were only met with silence. 

“Come on Shepard”, Kaidan muttered to himself before enabling his radio comms again, “Fireteam Alpha, this is Alenko. Confirmed survivors are human. Two personnel, one requires immediate CASEVAC. Acknowledge.”, asked Kaidan again. 

“Alenko, this is Overwatch. We lost contact with Fireteam Alpha. Kodiak is en route for CASEVAC, ETA 3 mikes. Once extraction is confirmed, proceed to Alpha's last known grid, over.” Anderson’s replies caused Kaidan concern, something he always failed to hide, and the armored figure seemed to be able to tell.

Seeing no other option, Kaidan decided to tell the truth.

“CASEVAC is coming, ETA 3 mikes. However, I need to rendezvous with my fireteam,” the armored figure only nodded at Kaidan’s words and proceeded to go back inside the crashed Pelican.

“Not much of a talker, are you?” commented Kaidan to particularly no one. The armored figure returned as fast as he left, now with a pistol that seemed to be magnetically attached to his hip, ammo pouches on his belt, and a rifle magnetically attached to his back, which caused Kaidan to put his hands back, ready to unholster his rifle.

“After CASEVAC extraction is confirmed, I’ll join you. You take point,” said the armored figure. Kaidan relaxed slightly but still kept his hands behind, ready.

“You are not part of the Systems Alliance Navy.”

“Consider it my gratitude for the aid.”

Kaidan wanted to argue with that, citing regulations and laws regarding mercenaries. However, he might as well accept the help of an extra man from a seven-feet-tall human with experimental armor tech. Besides, Kaidan’s gut told him this man was not the type that takes no for an answer when it comes to helping someone.

“Alright, Sierra. But you follow my orders. Understood?” The armored man nodded in response. Kaidan smiled to himself. Hopefully, with the help of this armored man, he could return to Shepard as soon as possible.


From all the things that are happening around him right now, Chief is somehow more miffed being called “Sierra” than the situation he and Esparza found themselves in. Joyeuse laughing over the comm when Kaidan called him “Sierra” didn’t help either. 

He is grateful that at least Kaidan couldn’t tell that he is bemused by his new nickname. 

Additionally, all the things that Kaidan said confirmed Joyeuse's hypothesis. They are as far from home as they could possibly be. He wonders how his team reacted to his sudden disappearance, how Halsey might be pulling an all-nighter to figure out how a Spartan disappeared during slipspace transit, and about the survivors on Installation 07. Both the Banished and Endless threats on the ring haven’t been fully dealt with, and the UNSC still has a lot of ground to cover to secure the ring.

However, that’s neither here nor there, Chief thought to himself. Right now, all he needs to focus on is getting Esparza evacuated and treated.

Three minutes passes and a blue square personnel aircraft descends down to the crash site. It’s half the size of the Pelican and as the door slides open, two men dressed in a familiar hue of navy blues and a woman, who Chief assumed to be a medical officer, steps down and coordinate with Kaidan to carry Esparza out. 

Except it’s not really a stretcher that he knew. Sure, it has the general shape of one, but Esparza's body hovers slightly in the air, a bluish hue enveloping him as if by magic. The Chief looked in amazement and concern; however, Kaidan could tell that the Chief had never seen something like that before.

“It’s a mass effect medical stabilization field. It’s safe,” commented Kaidan, which explained everything and nothing at the same time to the Chief. He asked Joyuese what Kaidan meant, but she only laughed.

“Chief, you need to adjust. All you have to do is ask Lieutenant Alenko over here,” replied Joyuese.

While the Chief knew that she was right, the middle of an active alien invasion was not the right place to ask questions about the world they were in right now. Both the Chief and Kaidan watched the Kodiak fly away, both men exchanging nods in satisfaction as extraction had been confirmed.

Kaidan unholstered his weapon from his back; the Chief observed as the weapon unfolded itself into a shape that was familiar to him.

“Okay, Sierra. Follow me,” ordered Kaidan.

“Affirmative, just one thing, Lieutenant.”

Kaidan turned back to face the Chief. “What is it?”

“Call me Chief.”

Kaidan laughed. “Only if you call me Alenko. Clear?”

The Chief nodded in reply. “Crystal.”

Both men faced the red-hued horizon of Eden Prime, picking up their pace with weapons at the ready. Having to follow a normal soldier's pace, a part of the Chief was left to his own devices, thinking that no matter which universe he was in right now, he would answer the call to protect humanity.

And another part of him wished he was not out of his depth in this universe.

Notes:

This was originally supposed to be a one-shot, because I haven't seen a Halo X Mass Effect crossover fanfiction that plucks Master Chief from his latest point in (game) canon to the earliest point of Mass Effect's game canon.

However, I had too much fun with it that I decided to turn this into a slightly full-fledged fanfic. God knows how frequently I will update it. Also, it is using a version of Shepard from my other fanfic (Under the Illusive Shadow), but it will not be connected to it; this one stands as a divergent of that story.