Guinea Pigs might be the best horror film screened at this year’s Edinburgh International Film Festival, and it does a good job of not seeming like one at all. The premise is simple: a group of seven arrive at a somewhat isolated clinic as volunteers for a medical trial. They’re the eponymous “guinea pigs”, and they’ll be living in the clinic for a week under inspection. Once the drugs start kicking in, though, some adverse effects start to show up, and the patients start losing their minds; and since it’s a double-blind test, nobody’s really sure who’ll be next to go. The film isn’t presented as “found footage” as the trailer led some to believe, but in traditional film format driven by a great ensemble cast, with a documentary-style text-based prologue.

The range of patients is wide, which is good for the ensemble dynamic: we have a female journalist; a “professional” guinea pig; a 19-year old student; an easily frightened man of Indian descent; a stereotypical douchebag with an audacious personality; and then the closest the film has to a leading pair, Adam (Aneurin Barnard) and Joni (Alex Reid). The group’s interactions with each other are reasonably limited by the restrictions of the trial – no sex, no alcohol – but their discussions around dinner lead to insight into their lives. Although some characters, like the 19-year old Carmen (Skye Lourie), remain remarkably underdeveloped throughout the film, it still feels like a better ensemble effort than in Contagion.

Guinea Pigs’ horror element doesn’t come out until the second half of the film, but once it does, it becomes an effective psychological horror. The only disappointment is in some underdeveloped potential, for example a lack of focus on the test’s double-blind nature, which should have led to some tension about who would be next to go. Instead, the group automatically assume they’re all going to become violently insane like first victim Jed (Oliver Coleman), until they find documents which confirm who in the group have been given placebos and who the actual drug, which suggests both patients and doctors forgot about the “double-blind” portion of the brief.

There are a few issues with continuity and flow which are made most evident when characters jump around the place: in particular, we cut away from a scene in which one subject is running terrified down a dark hallway, but she’s reunited with the others by the next time we see her, with no explanation of how she made her escape. It doesn’t quite feel like a plot hole, but it’s jarring enough that it makes the film feel a bit less cohesive. The film’s ending also goes in one of the few reasonable ways it can, but is a touch unsatisfying since there are still unanswered questions by the time the credits roll, which aren’t answered well enough by the super-imposed text at the end.

Aside from that, though, I found Guinea Pigs to be somewhat refreshing. The medical trial concept isn’t very well explored in horror right now, and while I’m confident it could have been executed better, it’s still a point on which to congratulate writer-director Ian Clark. As it stands, Guinea Pigs isn’t likely to win many awards or set new standards, but it seems exactly like the sort of film which can garner a cult following, and it gets me excited for whatever Clark has next in the pipeline. Those who like to eschew “traditional” horror in favour of more original works will want to check this out.