The year is 2186. The Weyland-Yutani corporation hold major contracts for urban pacification, core systems mining, rescue and salvage and most importantly, planet terraforming and colonisation.
The incident on LV426 where the entire population of the Hadley's Hope colony perished was now consigned to the ancient history category and most people weren't even aware of the existence of the derelict ship that had been found all those years ago. That ship now sits in a hangar in Weyland-Yutani's investigation centre. After the blast explosion ravaged most of LV426, a team was sent to evaluate the damage. They found the alien derelict slightly scorched but intact. The contents of the ship had been vaporised by the blast. No organic life could have survived. The Alpha rescue and salvage team transported the derelict vessel, affectionately nicknamed "The Boneship" due to its skeletal appearance.
In 2175, eleven years before the start of this story, a group of colonists attempted to seize control of the entire complex on the planetoid Marcoma. They situated themselves in a camp a few miles outside of the colony and staged regular raids on the mining and delivery craft that frequented the city. The colonisation committee decided enough was enough and enlisted the aid of the Colonial Marine Corps to restore peace to the planet. A fierce battle ensued and the rebels were easily pushed back by the marines.
Three weeks later, the entire camp of rebels was found dead, badly mutilated. Situated around the camp were the remains of several marines. Only one soul survived the onslaught. Major Aaron Kelly. He had managed to escape with his life but sustained massive injuries. As the only witness alive to tell the story of what happened, he was returned to the colonial marine headquarters and interrogated. Once they had finished with him they reassigned him to a training camp. He was to live out his remaining career time as an advisor and mentor to rookie marines.
The Marine commission closed the file on the case but Weyland-Yutani maintained a significant presence on Marcoma.
It was far from over.