In full, the plot of Aliens (1986) is a rescue story that turns into a siege and then a chase. Ripley is picked up after decades adrift and learns that LV-426 has been settled by colonists. She tells the company about the aliens, but nobody believes her. When the colony goes silent, she joins the Marine unit sent to investigate, together with Burke and the android Bishop.
At the colony the buildings are wrecked and there is only one survivor, a young girl called Newt. The Marines go into the alien nest and are ambushed, and most of them are killed. Their inexperienced commander panics, and Ripley takes over and gets the survivors out.
The group then learns two bad things. Burke wanted to bring back alien embryos for profit, and the colony's damaged reactor will soon blow up. The aliens take Newt, and Ripley goes back alone to find her. She reaches the girl in the hive and faces the alien queen there.
Ripley, Newt, Hicks and Bishop escape the colony shortly before it is destroyed. The queen, however, has stowed away on their ship and attacks them. Ripley fights her in a power loader and forces her out through an airlock. The survivors go back into hypersleep for the trip home.