It’s not the man afflicted with lycanthropy who struggles to come to terms with his inner wolf in The Beast Within. Instead, it’s his family that’s forced to interrogate what it means to live with an occasional monster in the narrative debut of filmmaker Alexander J. Farrell. Farrell, who co-wrote the screenplay with Greg Ellison, wields the werewolf as an on-the-nose monster metaphor, framing a family drama turned horror story from the perspective of a young girl discovering the harrowing truth about her father. It yields a dreamy Gothic fairy tale, even if defined solely by allegory.

Willow lives an isolated life nestled within a fortified compound deep within the English wilderness. That she’s also a sickly child, prone to terrifying respiratory issues that require oxygen tanks on standby, means that Willow doesn’t realize her remote existence isn’t normal. Of course, it helps that...