After the underlying tech for M3GAN is stolen and misused by a powerful defense contractor to create a military-grade weapon known as Amelia, 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.

Lorraine and Ed Warren travel to north London to help a single mother raising four children alone in a house plagued by malicious spirits.