Arkham Knightmares Season One Episode One: The Two Witches.

After barely escaping with his life, Chauncey is spirited away to a secluded room, where he meets a very unexpected ally. But can he trust the strange masked woman, or is she only out for herself? It might not matter in the end, as Chauncey has yet to encounter some of the more immediate dangers stalking the halls and corridors of the Manor...
What is that God awful chittering sound? And why does it seem to be getting closer...