The underlying tech for M3GAN has been stolen and misused by a powerful defense contractor to create a military-grade weapon known as Amelia, the ultimate killer infiltration spy. But as Amelia’s self-awareness increases, she becomes decidedly less interested in taking orders from humans. Or in keeping them around. With the future of human existence on the line, M3GAN's creator Gemma realizes that the only option is to resurrect M3GAN and give her a few upgrades, making her faster, stronger, and more lethal.