The agony of unyielding adherence to a faith is memorably dramatised in Daniel Kokotajlo’s debut feature. Apostasy would be compelling enough simply as a story of individual believers in a clash with institutional duty, but the film also unlooses a shocking gut-punch halfway through that will leave you winded for the remainder of its span. Not since Hitchcock’s Psycho (which also concerned the fate of two sisters) can I recall such a drastic jolt.