Using two iPhones and two talented lead performers, directors Powell Robinson and Patrick Robert Young have crafted a thoroughly engaging horror film with a heavy emphasis on characters. Threshold (2020) is fine independent filmmaking featuring improvised dialogue that feels lived in and boasts a jaw-dropping shocker of a climax.

Down-on-his-luck schoolteacher Leo (Joey Millin) is going through a divorce when his mother calls to say she has located his estranged sister Virginia (Madison West) and insists that he go pick her up. He reluctantly does so, and finds Virginia going through what he believes are substance abuse withdrawals, as part of the reason for their separation was her drug use. She insists that she has been clean for eight months and that what he is witnessing are the results of a cult ritual that got her off drugs. But now she is bonded to a male member of the group so that she can never truly escape the cult, and she feels whatever the male feels, and vice versa.

Naturally, Leo is highly skeptical of this story, but the two set out on a road trip to try and find the man to whom Virginia is bonded, with the agreement that she must immediately check into rehab if the trek is a bust. Though the second act may be slow going for viewers who have an aversion to slow-burn horror films, the acting and dialogue between West and Millin is intriguing and absorbing, heightening viewers’ investment in the siblings and setting up whatever may happen to them to be that much more arresting.

The majority of the film is, in fact, spending time with Virginia and Leo as they learn to reconnect through pumpkin carving, karaoke, an Ouija board session (as astute readers might surmise, never a good idea in a horror film but for a surprisingly different reason this time), and so on. Using ideas written by Young, the cast improvises most of the dialogue. The chemistry between West and Millin is captivating and so realistic that viewers can feel that this could be a real pair of siblings. The pair carry the film on their shoulders and do a spectacular job of it.

Using iPhones as the sole cameras for the film allows Robinson to get into intimate spaces between and around Leo and Virginia, and Threshold looks better than a lot of films shot with more expensive digital equipment. Careful attention to lighting is one of the reasons why.

The  climax and payoff are both super, and the journey getting there is a riveting one. Threshold raises the bar on what independent filmmakers can do with limited means and a small budget if vivid imaginations and talented cast and crew are involved.

Threshold will be released on  ARROW  in the U.K., U.S., and Canada on May 3, 2021.