|Release date(s)||April 1, 1996|
|Preceded by||Aliens: Alien Harvest|
|Followed by||Aliens: Labyrinth|
Escape from Charon or die in the grip of the ultimate weapon.
Welcome to the former penal colony of Charon, where a labyrinth of underground tunnels offer shelter to an Alien hive. Professor Ernst Kleist rules — a paranoid tyrant who sees and hears all. His speciality is making humans disappear...
Captain Joyce Palmer — instantly recognizable in her yellow Harley-Davidson cap — is bound for Charon. Only she and a few hand-picked marines can stop Kleist in his tracks. Only they can stop the professor's most insane creation — the ROGUE.
Commercial starship captain Joyce Palmer and her pilot Deegan arrive at the remote research station Charon Base, built within a vast maze of subterranean tunnels that used to house a convict facility. Palmer's latest job involves the transport of a mysterious Mr. Cray to the facility, the bountiful payment from which she intends to use to spend more time with her children on Earth. Upon landing, they are met by the scientist in charge of the facility, Dr. Kleist, who is experimenting with Xenomorphs that have created a large Hive in the miles of abandoned tunnels located beneath the surface of the moon. With several days to kill before returning to Earth, Joyce reacquaints herself with Hank, an old lover working at the base, but quickly learns that the local populace is living in fear — Kleist rules over the facility with an iron fist, his control enforced by his own private legion of security guards, and civilians at the colony have begun mysteriously disappearing. In reality, they are being used as Xenomorph hosts and victims in Kleist's experiments.
Also stationed at Charon Base is Sergeant Green and his contingent of Colonial Marines, whom Kleist has been using to recover live Xenomorphs from the Hive whenever he requires new specimens. Months of performing these dangerous duties has reduced Green's platoon to almost half its original number, and the death of another Marine on the latest excursion into the Hive causes one of his men, Chow, to snap and aggressively threaten Kleist. Shortly afterwards, Chow is captured by Larson, the leader of Kleist's security forces, shot in both legs and to die in the Hive as a host for the Xenomorphs. When Green learns his man has disappeared, he confronts Kleist himself and demands that he and his men be excused from duty and allowed to return home. Kleist agrees and Green and his mean gratefully load onto a shuttle for the return trip home.
However, Kleist double-crosses the Marines and remotely flies their shuttle into the Hive, intending for the Xenomorphs to wipe them out. Green and his men discover their ammunition has been switched for useless blanks, but have no alternative but to try and press through the Hive to reach the safety of the inhabited sections of the base. Sneaking down to the base of the Hive, Green and his men use explosives improvised from their blank ammunition to blast a hole through to the abandoned, uninhabited tunnels below, and then to seal the hole behind them. They escape the Hive before the Xenomorphs can catch up to them, but one of Green's men is killed in the blast.
Back in the civilian colony, Palmer and some of her friends at the base have launched a mutiny, determined to bring Kleist down. As they split up to recruit other willing mutineers, the final product of Kleist's research finally reveals itself — a ferociously powerful male human/Xenomorph hybrid, the Rogue, created through genetic experimentation intended to produce a controllable Xenomorph. When the creature makes contact with the nearby Queen, it smashes its way out of its cell and begins rampaging through Charon Base towards the Hive, seeking to destroy the Queen. As it relentlessly heads for her, it demolishes the main airlock leading into the Xenomorph-infested sections of the base, allowing the Queen's Warriors to swarm into the civilian colony. Larson's security forces attempt to hold them off, but are rapidly overwhelmed.
As Palmer and the other civilians formulate a plan of attack, they are joined by Green and his remaining men, who eagerly agree to assist in their escape from Charon. They raid the armory before splitting up, with Palmer heading for the hangar bay to secure her ship, half of the Marines heading for the living quarters to try and evacuate the innocent civilians, and Green and the remaining Marines making for Kleist's office to kill the Doctor and use his extensive security system to oversee the operation. Green finds Kleist has already fled, but discovers Larson in a side room and locks him inside with a Facehugger as revenge for his dead men.
Kleist has made for the Hive via a secret tunnel, determined to witness the battle between his creation and the Queen. However, the Queen defeats and kills the Rogue, causing Kleist to attack her with a Sound Cannon device designed to paralyze her. The device fails and Klesit is grievously wounded, with the Sound Cannon left overloading, its impending detonation set to destroy the entire base. Back at the colony, Palmer, Deegan, Green and the other survivors — of whom there are few — make it to Palmer's ship and flee the base moments before the overloading Sound Cannon destroys the entire facility.
After thoroughly checking the ship for any stowaway Xenomorphs, the crew enters hypersleep form the journey home, lamenting the loss of so many innocent lives at Charon Base.