It's pretty easy to imagine what the elevator pitch for the AppleTV+ horror series "Servant" was that helped give it the green light back in 2018. A troubled couple, reeling from an unimaginable tragedy that took the life of their infant son, struggle to move on with the help of a "reborn doll" and a mysterious young nanny who shows up on their doorstep. When the inanimate doll somehow turns into a living, breathing infant, the small family is plunged into the midst of much darker and...