Disclaimer: I do not own Halo or Infinite Stratos nor do I own their respective developers/publishers.

Chapter 1

Somewhere in Space…

In the vast blackness of space, a giant portal came out of the darkness, it was surrounded by deep glowing blue flames, inside of it, was also a pitch black color.

Suddenly, out of the portal, a huge spaceship emerges, the words UNSC Infinity were painted in white on it's side as a way to identify it when communications could not be established. This was the single largest and most powerful weapon humanity had and was made as a contingency plan against a theocratic group of aliens known as the Covenant, but it was repurposed as a exploratory vessel and was sent to this sector of space in order to scout out for any more planets that could be used by the newly-formed alliance between the UNSC and the now-allied Covenant.

The Covenant loyalist was now almost completely defeated, all that was left of it were very small pockets of resistance that the UNSC itself could handle even without the Separatists, who were busy helping with the restorations of the planets that they themselves had once destroyed and turned into a lifeless ball filled with nothing but glass. But they were forgiven and could now find a place amongst the humans of the UNSC without receiving death glares from said humans. But they still had to deal with some of the remaining rebels and possibly the return of the transformed precursors-better known as the flood.

Nonetheless, things were looking bright for the future of Aliens and Humans, at least the Separatist aliens, and they were currently looking for more planets that the growing human and alien population of the UNSC and Separatists could reside in.

The UNSC Infinity was on it's way back to the planet that had the origins of humanity, Earth, but they were in for a big surprise…..

Five Minutes earlier…..

Inside the Infinity…

"Roland, has the prototype Forerunner Slipspace engines been installed and readied for immediate activation yet?" The acting Captain of the Infinity, Thomas Lasky, asks a small orange glowing man that hovered above a pedestal.

"Yes Sir, we are ready for activation any time sir, Our destination?"

"Earth, we're being called in to test these new engines, the techs say that they are unsure just what exactly will happen once we use these things that we got from a Forerunner site but the Covie's Tech say that it should work even without modifications, we are the test-bed for these things as they were too large to fit in any other human ship as we are testing them on human ships only right now, and we are going to Earth to reduce any and possibly all risks of being attacked. But I'm sure you already know that."

"Affirmative sir, we can go now if you want."

"Alright then, let all hands know what we're planning to do."

"Yes sir." Roland said as he made an announcement over the P.A. Speakers.

"We will begin the test jump for the prototype engines in four minutes, get ready."

"Oh and Roland, how are those Spartan-IIs onboard?"

"The team assigned to be security detail? They are either at the firing range, or uh… the bar."

"What the heck would a Spartan-II do in a bar? Spartan-IVs I understand but IIs? They usually keep to themselves!"

"Sir the one in the bar was the one that we recovered a few years back while resupplying in Reach, we found him in a barely functional pod remember?"

"Oh, James huh? He's back here on security detail good to have the guy back, I hear he's the only one of the IIs that talk with people more than clean their guns and armor."

At the firing range of the Infinity

Four Seven-foot tall Green and black armored beings mounted to twenty-foot tall hulking silver Exosuits are walking around the range firing at their targets at the far end, one of the Mantis fire their newly armed Incineration Cannon and melt the target to ashes as well as a few more targets behind it and slightly burn the wall behind.

"These Mark X Mantis are exceptionally powerful, Impressive how they managed to connect our already heavily improved MJOLNIR Mark VII power armor to these fighting vehicles." John-117 or better known as the Master Chief says while piloting the new-model HRUNTING/YGGDRASIL Mark X Armor Defense System/ Powered Assault Exoskeleton or simply Mantis-II.

The Mantis was an 18 feet tall armored fighting vehicle that was heavily armed and very well protected to take on entire armies, both foot soldiers and vehicles with it's mounted machineguns and rocket launchers though it was only created after the Great Schism, in which the main Covenant was disbanded into Separatists and Loyalists, though it was sometimes used for cargo hauling, it still proved very deadly in combat, the second generation of the Mantis was still in it's prototype stage after integrating a lot of Covenant and Forerunner technology into the Mark-II, it was only available for the remaining Spartan-IIs as the other Spartans and soldiers could not handle the speed and stress of piloting such a machine.

The Mark-II was far more versatile, maneuverable, armored and much more heavily armed than the first generation of Manits, it was versatile in the sense that it could carry weapons in a backpack and eliminated the need to dock and manually change weapons, it was maneuverable that it could fly and go at supersonic speeds without the pilot fainting due to the thrusters and anti-gravity fields that are generated by the machine, it was made of stronger materials and had energy shields that could take three to five times more damage than the first generation and was faster in recharging than the old one and more heavily armed as it could be customized due to the option of getting Promethean and Covenant weapons for it aside from the default Machinegun and Rocket Launcher, the weapons customized for the Mantis had the name of the machine placed before the weapons' named, as well as being able to change it's color scheme in battle. But because of these improvements the Mantis-II had grown two more feet and was only pilotable by Spartan-IIs with their MJOLNIR Mark VII Powered Assault armor, which was also vastly improved compared to the MJOLNIR Mark-VI.

The MJOLNIR Mark VII had far stronger shields, the features on the armor like armor lock and active camo were all heavily improved and it augmented the Spartans' abilities even more than the Mark-VI, while testing the Mark-VII Spartan-II Frederic-104 took down Twenty Sangheili Zealots in CQC and Knife Combat , the Sangheili were all knocked unconscious making it apparent that said Spartan was merely holding his strength back. While testing the same suit Kelly-087 could run up to 80 mph, a speed considered far above what even the augmented human body could handle, the reaction times of the Spartan-IIs testing the armor were so fast that they could catch Sniper bullets mid-air and throw them back with enough speed and power that it dug five meters inside a concrete wall, the shields could handle a whole Spartan laser if fully charged. It was even tested to allow the wearer to survive the heat of orbital jumps, providing that the wearer is able to activate the improved and very powerful Jetpack before impact, the jetpack of the Mark-VII was designed to give enough thrust to the user and suit that it could slowdown falls even from Orbital jumps, these were used in lieu of the much more dangerous HEVs as it was proven to be safer .

"Yes squad leader, I'll say, the tech guys were even kind enough to give mine a pair of energy swords about my size." Frederic mentions while taking out and activating an oversized energy sword meant for the Spartan-mounted Mantis.

"They also gave mine a large Blue Sentinel beam to boot; they are pretty serious about security as these Mantises were modified to fight in space as well." One of the Spartans with 058 in her armor also says.

"These exoskeletons were also given very powerful thrusters on the key areas and minor anti-gravity generators to make Super-sonic flight very possible, they say even Spartan-IVs couldn't handle the speed and maneuverability that these provide even with their reaction times augmented."

"Well that's enough training for now, we have already done some practice flights outside the ship and we should be ready, we'll be entering slipspace a few minutes from now so get ready for what will happen since the FTL drives on this ship are new and it is more likely than not that the Insurrectionists will attack or maybe even the few pockets of Loyalists around."

At this time, an announcement came from the P.A. Speakers.

"This is the Captain, we will be entering Slipspace in Five seconds…."

"Well, we should get ready, but where is James? Although I am glad that we found him surviving in a pod after we had to leave him but he seems more carefree than he was before, though I hope he still has his edge." One of the Spartans say.

"Five…. Four…. Portal opening… Three…. Two….. One… Jump engaged."

In the present….

The bridge of the Infinity

After the slipspace jump, everything seemed to be normal to the crew and captain, until the A.I. of the ship contacted Earth's command.

"Sir…. There seems to be a problem…" The Infinity's A.I. Roland mentions to the Captain.

"Huh? What is it Roland? Everything here is fine according to the data."

"Sir, I've lost contact with the UNSC High Command…. My scans show that… this is unbelievable…."

"What is it?" Thomas Lasky asks, obviously wondering what they've got themselves into.

"According to my data and all the tests that I have performed regarding what to do with the data…. We have travelled to an alternate reality."

The Captain's eyes widen in shock.

"What do you mean? The coordinates are the exact ones that we normally use for Earth! How exactly did you determine that we are in a different Reality?!"

"The all the channels that we use in the UNSC are not working, meaning it is not picking up anything, only static, which is next to impossible, as the only way that can happen, is either everyone on that planet had been evacuated or completely disappeared or something is jamming our communications, which I can safely say is not happening, plus, all the 200 or so Orbital Platforms that usually surround Earth is completely gone, no wrecks, no emergency transmissions, no nothing, but I am picking up signs of life on Earth, but much like how the Earth in the Twenty-first Century was, and as I have said, all the test that I have performed according to this could only mean that we have travelled to what is called an "Alternate Reality"

"Give me some time first to review the data… if what you say it true then I will have a hell of a time explaining it to the crew.."

A few hours later…..

The meeting called by the Captain lasted for quite a while, with many crew members finding it impossible to believe that they had travelled through another reality and were already thinking of ways to get back to their reality and families, but some were more optimistic and wanted to seize the opportunity, the Spartan-II security detail kept to themselves as usual although….

In the Firing range….

"Squad leader, if we are really in another reality as the captain said so then shouldn't we make contact with the people in this version of Earth and look to find a way to get back to UNSC space, or we could look for the cause of this event and see if we can get back?"

"That is true, but I doubt we are going back anytime soon as everything went normally as far as I can determine during that jump, I reviewed the data as well and it all came back normal, this might have been caused by that prototype Forerunner engines implemented on this ship and it's physics which is not fully understood by our scientists yet."

"Well, It might also be that you luck seemed to be too much this time squad leader, we have got an entire system to colonize and wars to fight, back there in our UNSC there wasn't much fights anyway and I'm guessing we would have been discharged for civilian life, which I might have experience at talking to the Marines at the bar but I don't feel any less uncomfortable than you and to be honest we Spartans belong to the battlefield." James-005 walked through the door of the range then joined in to the conversation via SQUADCOM.

The other Spartans stopped and went into thought as they wondered over James' words. He was right after all, they didn't have much of a place among the civilian populace back in the UNSC and their muscles could ache due to the pain of the augmentations still there and the only thing that cause ease their pain was the adrenaline rush of battle.

Meanwhile…

At the bridge of the Infinity….

The Captain was on his chair reviewing all the data on the planet that they were currently orbiting above.

This was in fact Earth, but not THEIR Earth, it was similar to it but it did not have the UNSC as their Earth, Mars and the other planets in the Sol System were also not colonize unlike in the UNSC, all the planets in the Sol system were terraformed and made habitable and were home to thriving colonies of humans and a few of the Covenant races.

It was then that the Captain made a decision.

"Roland, we will conduct surface investigation, I want the Spartan-IIs on this ship to get to the surface and gather more information about this reality, it's similarities and differences to our Earth, but we will probably be here for a while as we have no way to know exactly what happened here since even the Huragoks are having trouble finding out the reason why we ended up here during what was supposed to be regular slipspace jump."

"Affirmative sir, sending orders now."

Back in the Firing Range….

"I'm not really sure about this James, but I guess we have no choice in the matter as we are stuck here in the meantime… we have received direct orders from the Captain, we are to ready up and head planetside, get your Mantises ready and we move in a few minutes, Blue team move out!"

Three minutes later…..

The Spartans all went to the armory after their leader issued the order to get ready, they all got different weapons that suits their specialties.

Fred kept his two energy swords and a Mantis Suppressor, as well as two Combat Knives and an MA5D with the grenade launcher attachment and a Covenant Plasma Pistol in case he had to ditch the Exoskeleton, as they had many more in stock in the Infinity and the Huragok were well-versed in making the machines. Linda took a Mantis Binary Rifle for her Exoskeleton and a Sniper Rifle and M6D sidearm for emergencies.

Kelly brought a Mantis M45D Shotgun and a MA5D and Spartan Laser. John kept his Incineration Cannon and got the Mantis Storm rifle, he got a Spartan Laser and Scattershot for operations without his Mantis-II.

They were now ready to set foot on this reality's Earth…

End of Chapter.

This had been an idea floating around my head for quite a while, so I just had to put it down here.

As you can see, In this chapter, it makes no mention in what happens inside the Infinite Stratos World, the reason for this is that I am not yet sure on where exactly will I place these Spartans in, I am taking suggestions and ideas just make it clear and explain why it is a good time to plant these Spartans in, though if there will be no responses I am capable of determining the entry point, though that will take quite a while.