Five minutes into Austrian directing duo Veronica Franz and Severin Fiala (Goodnight Mommy, The Lodge)’s third feature Des Teufels Bad (The Devil’s Bath), you know this period piece is not going to be an easy watch. And for good reason. Upper Austria. 1750. A punishingly bleak prologue sees a mother traverse the woods, and head towards a waterfall. There, without batting an eyelid, she throws her screaming infant off the ledge. She then heads to the church, knocks on the door, and turns herself in to the authorities. “I have committed a crime.” She is executed. More precisely, she is decapitat…