In the mountains of Thailand is a shrine to an ancestral spirit, Bayan, and her shaman, Nim (Sawanee Utoomma), who works as a seamstress in the nearby town.  As is tradition, Bayan selects a female in the family line to possess and fill the role of the spirit’s shaman, but the process causes a lot of pain and physical changes in the new ward.  These changes begin happening to Mink (Narilya Gulmongkolpech), Nim’s niece, but as the process continues and the symptoms grow more and more severe, Nim begins to question if it is really Bayan seeking to make a vessel out of Mink or if it is something much darker. 

The Medium is a found footage, documentary-style horror film directed by Banjong Pisanthanakun.  Written by Pisanthanakun as well as Chantavit Dhanasevi and Na Hong-jin – the latter of whom found western success as the writer/director of The Wailing (2016) – the film covers a lot of ground in its 130-minute duration creating a genuinely creepy atmosphere before pulling out the stops on an expertly crafted finale that utilizes many of the horror tropes to great success by bending them to fit into the overall narrative.  

The horror script starts off very grounded and introduces audiences to the rules of the world. With Nim’s warm and kind presence, they pull back the curtain on some aspects of Thai spirituality and try to break down some of the stereotypes, even within modern-day Thailand, about the role of shamans in today’s world. Utoomma delivers an incredibly grounded performance as the titular medium, and it is her calming energy that lulls us into the story before it takes a dark and wild turn. Even in the midst of the latter chaos of the film, we return to Nim not only as a source of exposition to explain what is going on, but her entire arc as she grapples with the idea of giving up Bayan and what that means for the trajectory of her life is incredibly interesting. Ultimately, she does take a back seat as the story unfolds but framing The Medium around this transference really makes it stand out from being just another found footage film looking to turn a quick buck.  

The latter half of the film seeks to identify the spirit which has taken Mink hostage, and this is where it begins to lean more into the traditional horror elements. Admittedly, this middle act runs a little long and feels repetitive as – at least for Western audiences – many of these same tricks and tropes can be found in any number of straight-to-dvd exorcism movies from the early 2000s. The script does ask a lot from Gulmongkolpech, and she delivers a very unsettling and physical performance as the spirit becomes more and more aggressive with her.  She guides Mink through the various stages of her possession, starting at first with what appears to just be angst, turning into more overt outbursts of rageful energy, and then finally her succumbing to the vengeful whims of the spirit. While we never learn the name of the spirit which has taken her, there is still a human backstory that is revealed and, like how Nim’s humanity carries the first act, the human-rooted mystery of how this possession was able to happen is what drives the middle act. In that sense, this spirit is not a completely nameless vengeance, but it has its own reasoning on why it targeted Mink for a host. 

Where Pisanthanakun really takes a stand and ups the stakes of the film is in the third act when the family resolves to perform an exorcism on Mink. The documentary crew sets up some night-vision cameras in the home to monitor what exactly it is that Mink is doing in the wee hours. It all starts out simply enough, she creeps around throwing things left and right, making a true mess of the place, but as the exorcism date grows nearer, the spirit becomes bolder, and the antics witnessed really start to push the boundary of what we are used to seeing in these films. The format of these night scenes may remain the same but Pisanthanakun, both behind the camera and on the page, creates such a feeling of dread and discomfort at what we are watching yet it is hypnotic, and we cannot take our eyes off the screen. We cannot take our eyes off Mink lest she sneaks up behind us.   

Pisanthanakun, however, is just getting started as he pulls out all of the stops for the ritualistic finale. The most satisfying thing about this final act is how it is a coming together of all three major aspects of the film: the documentary style, the straight horror elements, and being able to showcase the rich colors and artistry of the Thai people. While at times during the first half of the film, the documentary approach seemed to hinder the story – often just falling back on it for easy exposition, but then not holding to that outsider perspective during much of the plotting – it is used to great effect here in the last thirty or so minutes and really highlights the strength of this style. 

The Medium is a surprisingly sprawling work that slowly but surely ratchets up the tension and delivers some solid scares. Pisanthanakun and his crew expertly build the tension of the film in a slow and deliberate manner so that we, even despite our own knowledge that we are watching a film, begin to believe the story they are telling to be true. Because they spend so much time building up the human elements of the narrative, they are able to find great success when they fracture the family drama to introduce the supernatural. In utilizing impressive restraint during the buildup, the absolute wildness of the third act works as a perverse form of catharsis. The evil is no longer able to be ignored, it is no longer hiding in the shadows of our peripheral.