Faith builds a chilling atmosphere, first by emotionally isolating her protagonist then by letting her get lost in the winding halls of a near-abandoned hospital. The blackout enhances the setting’s disorienting nature, with the nervous nurse growing more frantic as she rushes to find the next sliver of light cast by a selectively placed generator. Those large stretches between the generator’s red glow or candlelit wards create a vacuum for encroaching terror—the more the hours tick by, the less reprieve Val receives. The filmmaker demonstrates a thrilling ability to mount dread and suspense while ratcheting up Val’s psychological stakes. Faith escalates Val’s story at a brisk and steady clip.