It appears I am King under the mountain this time around...if only it were a joyous occasion.
I felt this story, I think its a subtle sort of horror in that there wasn't any great surprise you could see it coming from a mile off. There was nothing to be done, no warning that could have been effective, that long slow ride into the dark is most chilling.
For me the voice could have been either the witch, Hansel's sister or even his own conscience* and it makes little difference. I suppose it ought to be worrisome if it was the witch, which indicates that perhaps it was not her choice either. Maybe that even provides an excuse, not a good excuse, but one nevertheless for Hansel. He had so very many chances to escape and never took one, from after their escape, their first chance to get away as opposed to returning and not turning away when horror was still in the distance.
Quite a bit to chew on here, I'd say.
I do think when the darkness smiles and bows to lead you inside is far more terrifying than the beasts of bone and sinew.
* Isn't it fascinating that conscience is con science?