A group of cave explorers are confronted in an underground cavern by a mysterious living rock. Little do they know that it bears home to deadly, flesh-eating creatures, intent on wiping out the entire human population. An ultra low-budget, unofficial and unauthorized sequel to the 1979 film Alien, although the plot has little connection to the original film.

Advent is a sequel to Alien: Covenant in which David sends a transmission from the Covenant to Weyland-Yutani on Earth, elaborating upon the genetic experimentation he has been conducting on Planet 4.

Created to mark the two-year anniversary of Alien: Covenant's home video release, the film is a sequel to the movie in which a Weyland-Yutani team arrives to investigate David's laboratory on Planet 4. One of the explorers enters David's laboratory to document the rogue synthetic's scientific discoveries. After carefully recording the specimens and records within the lab, including dissected Neomorphs and a vial of black liquid, he sets up his camera to analyze an egg-like object in one corner of the room while he continues his visual examination of the room. As the analysis continues, the Egg begins to show signs of life.

Two childhood best friends are asked to share a kiss for the purposes of a student short film. Soon, a lingering doubt sets in, confronting both men with their preferences, threatening the brotherhood of their social circle, and, eventually, changing their lives.