The Battle of the Mid-Galaxy Void

Pre-Battle
A Loki-Class Stealth Frigate under UNSC Service made its way into Sol, making a swing past saturn. It was to engage a insurrectionist group preparing a raid on mars along with a Halcylon, apon reaching mars, they found no traces of insurrection on the planet, and returned to earth to refit for a scanning mission, apon reaching earth, they got a refit and instead of scanning mars, were send to Sigma Octanus IV to assist in the battle.

Battle of Sigma-Octanus IV
Slip-Space portals opened across the frontal deck of the station, and a massive covenant fleet exited each. The station called for the fleet to be assembled into a single battlegroup and sent in, and as the Loki-Class entered battle, it sustained a MAC overheat, blowing up the frontal section. It attempted to slipspace away, and it did. It wasn't seen at earth yet, and they assumed it didn't make it through. Meanwhile, the battle raged on and the halcylon set up rescue teams and tracked the Loki down.

The Mid-Galaxy Void
Apon exiting hyperspace, the loki suffered a hull breach near the engine room, but no major damage. To the crew's suprise, they saw the MAC didn't overheat, but was sabotaged, it was easily repaired and the Loki sat in the void, devoid of stars and the only visible light source were the repair team's headlights and the two galaxies of Andromeda and The Milky Way, they all sat in wait, just as the halcylon exited hyperspace next to it.

"Loki, respond"

"We hear you, thanks for the rescue, but our slipspace drive is useless, yours?"

"Ours is fine, we'll begin repairs on yours right away"

"Thanks"

"Hey, Loki, Might wanna watch out, strange signals coming off my bow"

Out of nowhere, three massive unknown ships shaped as "Triangles" with guns, ion cannons and a towering bridge with dual shield generators.

-Lord, it seems we've been cut short, is there a problem?-

-No, It was supposed to be a hull checking stop on the trip, but we found them-

-Want us to man the cannons, lord?-

-Send them a warning first, captain-

-Yes, my lord-

A warning was transmitted from the ship to the halcylon.

"Loki, transmission received, shall we answer?"

"Aye, seems the best thing to do"

"This is the UNSC Pride of Eridani, who may you be?"

-We're the ones asking the questions, after all, we have the superior fleet-

"I'm not so sure about that, but go on."

-We are of the imperial navy, you are to clear out of this area immediately or be destroyed-

"Can't, our frigate's slipspace drive is busted"

-Too bad.-

The three triangular ships moved into position, and the halcylon fired a single MAC shot at one's bridge, blowing it to bits, the Loki's archers opened up and did significant damage to one of the triangular ship's weaponry. Longswords were launched and dealt with incoming Bow-Tie shaped fighters, and they were barely a match for the longswords, untill distorted, spikey bow-tie shaped fighters exited, The halcylon was hit by an ion shot to its bridge, it loosing all control over its weapons and it quickly started to be destroyed.

"Repairs done, ready for retreat?"

"Alright, lets hope this works"

The Loki and the Halcylon went into slipspace, escaping from the triangles, and arrived at earth. But before they could celebrate, the triangles had followed them. Lucky for the UNSC, they had arrived on a planet ringed by smacs, massive fleets and longswords as far as the eye can see. The triangles were no match for earth's defense, and all three were destroyed. This was the only recorded contact with extra-galactic species so far, and humanity had already seen their feriocity, however, the covenant was a much larger threat and no time was spend defending the galaxy's border. The "Imperial navy" neither.