The alien is a member of the alien species that is the main enemy in the Aliens movie series. The crew of a ship bound for Earth encounters them when the ship warns them of a sign of life on a nearby planet. A larval version clings to the face of one of the scientists visiting the planet and won’t let go. The others bring it back on board despite the warnings of the scientific officer who insists on quarantining it. He doesn’t survive, but the alien still took the opportunity to lay an egg inside him and when it hatches and comes out of the man’s body, it’s the beginning of chaos.