It take places 5 years after the events of Monsters, Inc. and 26 years after the events of Alien: Romulus, since the Xenomorphs and its alien species are taking over the world, invading Monstropolis and exterminate the monsters, Mike and Sulley are teamed up with the other monsters, facing off against the evil queen Xenomorph, during the alien invasion incident of Monstropolis.
