A brilliant toy company roboticist uses artificial intelligence to develop M3GAN, a life-like doll programmed to emotionally bond with her newly orphaned niece. But when the doll's programming works too well, she becomes overprotective of her new friend with terrifying results.
Following the events at home, the Abbott family now face the terrors of the outside world. Forced to venture into the unknown, they realize that the creatures that hunt by sound are not the only threats that lurk beyond the sand path.