On an epic adventure across a postapocalyptic world, a lovable boy who's part human and part deer searches for family and home with a gruff protector.

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.