Theory about the show

I think it is pretty clear that the evil entity in the forest wants the people of the town to sacrifice children so they can be set free. They told Sarah to kill Ethan but she couldn’t. Tabitha sees children that were previously sacrificed by the people who used to live there before and the monsters are those who participated in this ritual. Whatever the big bad evil is behind this… they want child sacrifice and this is why the monsters are trying to break Boyd as he is the leader of the town. Once Boyd is truly broken, he will willingly sacrifice every child to make sure everyone else gets to go home. If they do decide to this horrible thing… they will become the monster and the town will reset and new batch will come in.