Two years after M3GAN's rampage, her creator, Gemma, resorts to resurrecting her infamous creation in order to take down Amelia, the military-grade weapon who was built by a defense contractor who stole M3GAN's underlying tech.

After a global apocalypse, an android called "Mother" is responsible for repopulating Earth using a collection of embryos stored in an underground failsafe bunker. Her teenage daughter, who she raised from an embryo, is submitted to classes and tests to assess her development as human being. When the daughter finds a mouse inside the base, she suspects that the outside is no longer contaminated. One day, she sees a wounded woman outside the base and lets her in. Soon she learns something that will affect her relationship with Mother and which will change her forever.

When his dysfunctional family clashes over the holidays, young Max (Emjay Anthony) is disillusioned and turns his back on Christmas. Little does he know, this lack of festive spirit has unleashed the wrath of Krampus: a demonic force of ancient evil intent on punishing non-believers. All hell breaks loose as beloved holiday icons take on a monstrous life of their own, laying siege to the fractured family's home and forcing them to fight for each other if they hope to survive.