M3GAN is a technological miracle, a cyber doll whose artificial intelligence is programmed to be the ideal companion for children and the safest ally for parents. Designed by Gemma, the brilliant roboticist from a toy company, M3GAN can listen, observe and learn while becoming both friend and teacher, playmate and protector of the child she is bonded to. . When Gemma suddenly becomes responsible for her 8-year-old niece, Cady, whose parents have suddenly passed away, she’s definitely not ready for her role. Overwhelmed and under pressure at work, she decides to tie her M3GAN prototype to the little girl, in a desperate attempt to solve her problems on both fronts. A decision that will have terrible consequences.