Opening with a proverb concerning two wolves “at war with each other,” The Beast Within is a moody, atmospheric film. This slow-burner is the first genre film from Alexander J. Farrell. The co-writer/director has previously helmed two feature documentaries, a film for television, and several shorts. With this film, Farrell seeks to enter the most accessible genre for a starting fiction director: horror.
As films from the perspective of girls and women are popular these days, our perspective is guided by Willow (Caolinn Springall). She suffers from a breathing condition that requires the daily use of oxygen. She can go hours between bouts of her oxygen tank. However, if something shocks or scares her, she needs oxygen directly. Willow lives on a pig farm in rural Scotland with mother Imogen (Ashleigh Cummings), father William (Kit Harington), and grandpa Waylon (the unflappable James Cosmo).
Every time a full moon rises in the sky, Imogen takes William to a secluded ruin in the woods. He is chained there, and then something horrifying occurs. As this is all Willow knows, this is what the audience learns. Tension comes to a head after Willow chooses to follow her parents one night and discovers the secret that her father has been hiding all these years.

“…Willow chooses to follow her parents one night and discovers the secret that her father has been hiding…”
Where The Beast Within departs from the time-honored traditions of this sort of monster film is twofold. First, Farrell is less interested in the actual transformation but rather in the growing sense of dread that surrounds the events of each full moon. Second, the behavior of the one subject to transform: William is a kind man, even somewhat sweet. However, there’s a latent primal violence rippling beneath his sweet exterior. This threatens to manifest during a scene where Willow asks to help him chop wood.
The Beast Within is one of the tensest slow burners I have ever witnessed. Every time Harrington is on the screen, hackles raised on the back of my neck, gentle reader. He’s an actor who can convey latent fury and violence just through his facial tics and eyes. Springall is an outstanding young actress and carries the narrative throughline very effectively. However, the acting is only ever a part of the equation.
Farrell and co-writer Greer Ellison have built a fully developed, well-aged folk horror forest for all the creepy events to occur. This has the dark and malevolent magic of the old world, coupled with the rugged and bucolic beauty of the Scottish highlands ranging from its mountains to its ancient deciduous forests. Further, Farrell is an excellent and subtle director. There are no huge flourishes, no needless bombast. Every action is well-conceived and thoughtful. The rhythm imbued by the once-a-month lockups in the ruin ties the supernatural and horror elements together effectively. This is a fantastic entry to the genre for the director.
Ultimately, The Beast Within is a tale of a family threatening to fracture. It’s no one’s fault per se. It’s just very hard to build a life around a transformation curse. This is by far and away the tensest of slow burns. Seek it out if you want to see a deeply atmospheric family drama.