My first attempt at fan fiction; I prefer original work. Critique is requested. Mass Effect (c) Bioware Warhammer 40k (c) Games Workshop

The Outsiders

Just after the Suicide Mission

Commander Shepard looked out the Normandy's main viewport at the planet below. Eta Ro III was a garden world on the edge of the galaxy, beyond space claimed by either the Citadel or the Terminus systems. "Looks like a nice enough place from up here," Joker, the ship's pilot, said. "Of course, it isn't slated for colonization, so there are probably man-eating dinosaurs or poisonous food, something like that."

A holographic circular icon appeared on the console before them. "The survey teams reported no major environmental hazards," EDI, the ship's AI, stated. "The Alliance's science station has operated without incident for four years. It is only the planet's extreme isolation that has prevented colonization."

"I don't buy it," Joker responded, "There are plenty of people who'd like to get out away from everything, especially on a world like this. I mean, it's practically paradise, there has to be some dark secret."

"We'll find out when we get down there," Shepard said. He turned to the ships CIC. "Joker, you have the bridge. Don't scratch the paint."

The team assembled in the main launch bay. They had all physically recovered from the high-risk mission through the Omega-4 relay, which had ended in remarkable success. Now, they were an elite unit capable of any mission, and dedicated to one purpose.

The Reapers were an ancient race of machine ships, who upheld a galactic cycle on extinction. Every time sentient life rose to the point of galactic influence using the Mass Relays and the Citadel, the Reapers would awaken from their eon-long hibernation and purge the galaxy. Their reasons were their own, and they had decided it was once again time.

Commander Shepard had learned of this, hunting down the rogue alien agent Saren Arterius. Since then, he had dedicated all of his energy to stopping their genocidal agenda. When the Citadel Council, the ruling body of the peaceful interstellar community, failed to produce the resources he needed, Cerberus, a shadowy organization dedicated to the advancement of the human race, offered to help him. Despite his reservations concerning the operations of Cerberus, Shepard realized he had no choice. With Cerberus' aid, he had led this team to take out the Collectors, pawns of the Reapers. Now, they were here at the edge of the galaxy to investigate a possible new ally.

Miranda Lawson, the senior Cerberus operative aboard the Normandy, stepped forward. "Cerberus intel doesn't have much on the Eta Ro III installation. The Alliance has kept this secret impressively well. The briefing mentioned something about encounters with an unknown alien race?"

"Admiral Hackett didn't say much over the comm," Shepard responded. "I'm not sure if he was concerned about the security of the transmission, or if he didn't know himself. Dr. Marchesini on the surface will know more."

"Sounds like a nice, quiet mission for once," Garrus Vakarian, the Turian marksman said. "Of course, they never turn out that way, but one can hope."

The shuttle touched down at the Alliance installation, a complex consisting of a dozen modular pre-fab structures. Soldiers of the Alliance stood around the perimeter, as though they were expecting an attack at any moment. As they disembarked, a group of armed LOKI mechs approached, escorting an Alliance officer and a scientist. "Commander Shepard, it is good that you are here. I am Dr. Marchesini," the scientist said. "This is Cpt. Arnold Church."

The captain saluted. "Commander Shepard. I've heard about your service on Elysium and during the Geth attack on the Citadel. It's an honor."

"What's the situation here?" Shepard asked.

"We've observed several vessels at the edge of the system, their power signature and profiles unknown," Dr. Marchesini explained. "We were about to attempt to make contact with them when the Geth arrived."

"Were you attacked? How did you hold out?" Shepard asked.

"We repelled the first attack, but I don't think it was an actual assault," Cpt. Church responded. "Felt more like a probe."

"There's more." Dr. Marchesini led them to a display. "A few hours ago, we detected a geth dropship incoming. 30 kilometers out, it was hit by ground-based fire of unknown origin. We believe it may be our unknown aliens."

*******
The Mako sped through the jungle, its engines roaring. Swerving around larger areas of vegetation, Commander Shepard still maintained a fairly straight course to the coordinates Dr. Marchesini gave him. "I never understood why you always push your vehicles to nearly unsafe velocities," the Quarian engineer Tali'Zorah vas Normandy said from the back seat.

"Must be a human thing," Garrus responded. Shepard only smirked and shifted into the next gear.

They arrived at the site of the crashed Geth ship. According to the intel from Captain Church, it had been shot down by fire of unknown origin, and there was a good chance it was these unknown aliens.

Shepard brought the Mako to a stop next to the burnt wreck. They disembarked; Shepard and Garrus scanned the perimeter with their weapon scopes. A score of Geth bipedal platforms lay charred and scattered all over the clearing. Debris from several larger Armature platforms was also visible, though they had been completely blown apart. There were no active signatures.

Tali kneeled down next to a comparatively undamaged, but very dead, Geth. She began to examine it with her omnitool. "Based on these readings, I'd say the primary source of damage was heat, although there was a significant kinetic force accompanying it. The round was much hotter than what our weapons are capable of. If I had to guess, I'd say a plasma weapon."

"The Geth possess weapons that make use of plasma. Cerberus recovered a shotgun that created plasma induction on impact," Garrus said.

"It's possible," Tali responded. She began to examine the armature wreckage. "This was done by a mass accelerator weapon. A very powerful mass accelerator weapon. Bigger than a Mako's gun, at least. Some of these have scorch marks that indicate explosives, probably rockets."

"Look at this," Shepard said, examining a depression in the ground. It was a four-toed footprint, larger and heavier than any humanoid and too regular. "This is too big to be made by any race I'm familiar with, even krogan."

"I found similiar ones, but much smaller," Garrus replied. "I'm guessing that was made by some sort of machine."

"Whoever did this, they hit hard. Doesn't look like the Geth stood a chance. I don't see any other bodies," Shepard said.

"You're right. Whoever did this managed to shoot down a Geth dropship, then slaughter its compliment without sustaining a single casualty. Damn, that's one effective operation," Garrus responded.

"I've gathered all the data I can," Tali said after investigating the downed dropship. "I can analyze it at the-"

"Shepard, this is Dr. Marchesini! The Geth are back, and attacking in force! We can't..." The transmission cut off.

"Everyone! We're heading back to base!" Shepard ordered, and they piled back into the Mako. It spun about and accelerated back the way it came.

A pair of red lights, vertically aligned, shone out from the foliage surrounding the crash site. Other pairs appeared beside it, before they disappeared back into the jungle.