Acheron (LV-426) is one of three known moons orbiting the Calpamos, which is located in the Zeta II Reticuli system, 39 light years from Earth. The moon is christened by human colonists as Acheron.
The Jordan family sent to investigate a set of coordinates on company orders, discovered the Derelict, apparently untouched since the Nostromo incident fifty-seven years earlier. A facehugger impregnated the father, Russ, when he and his wife explored the Derelict. Under orders from Carter Burke, the colonists investigated the Xenomorph eggs and a large number of colonists were 'facehugged' so that the species could be studied. Four dead facehuggers were kept preserved, and two live ones were removed before embryo implantation, at the cost of the lives of their hosts. However, the humans who were impregnated released chestbursters which matured and established a hive in sub-level 3 of the Hadley's Hope atmosphere processor. The Xenomorphs killed or captured, cocooned and impregnated many of the colonists, and one of the Xenomorphs grew into a Queen and started producing more eggs.
The Alien Society was Founded on Acheron, Including our Founders, The Matriarch, Drej Queen and her Commander, And even the Elder Aliens around the Council to Mobilize their New Army of Aliens. Few of the Remnants Bursts the Chestbursters and transformed into Drones, Warriors and Praetorians.
In the Ultimate Battle of LV-426, a Colonial Marines squad, including Lieutenant Ellen Ripley, arrived on LV-426 to attack all but Flying Xenomorph Carriers, and Flying Machines Blockaded the Atmosphere, The Colonial Marines Deploy Six of the Dropships led by Tarr Seirr to attack countless Separatist Droid Armies, Aliens, and Nightmare Dream Eaters.
Ripley and her Soldiers met The Matriarch, and Her Council. Ripley threatened to destroy all of the eggs in the Royal Chamber if she, Tarr Seirr, their Rebel Troops and Colonial Marines attacked, and the Matriarch signaled her circling warriors to let them leave. But, when one of the eggs hatched, Ripley incinerated the eggs with her flamethrower and shot the Matriarch's Eggsack with her grenade launcher. Enraged, the Matriarch detached herself from her eggsack and pursued the fleeing humans through the increasingly unstable structure.
As the Battle Continues, Ripley and her armies flees as the Matriarch chased after them. With the Battle ends, the creatures' hive was destroyed when the atmospheric processor's power source exploded. Xeno-Dracus Found the Matriarch and returns to Xenonaira, Which the enemy flees from Heavily-Damaged Sulaco, and its Alliance Fleet.