The STD as the delivery mechanism for horror isn't a completely new invention by any means. Cronenberg's classic, Shivers, along with the very well done and unfortunately under recognized Contracted (currently available to stream on Netflix) use it, but It Follows strays away from the kind of body/biological horror the other films of this variety use and instead heads off into supernatural territory. Shockingly enough, as horrifying as they are in real life, STD's aren't an often used story element in horror or sci-fi, which works in the films favor. Heading away from the science fiction aspects that have been at the center of previous films that have attempted to incorporate STD's, puts even the more seasoned film goer at the disadvantage (or advantage, depending on the particular viewers preference) of not being able to refer to previous incarnations of the idea for frames of reference as to where the story might be going. That alone is an unusual feat and deserves recognition.
The It of It Follows is never fully explained, which is to film maker David Robert Mitchell's credit. The basic conceit at the center of the story being that one character transfers the attentions of the shape shifting It to another through intercourse. It is going to follow until It kills you. It can look like anyone and the only way to get rid of It is to give It to someone else.
This is not a film as concerned with neatly tying up it's story and plot as it is with putting the audience through the experience of It following. The success of the film and it's often unsettling and sometimes genuinely frightening moments are due to that focus. Where most other horror films are obsessed with the origin of the horror, vanquishing it and the story that happens in between those two points, It Follows leaves basically all of those tropes behind. What we're told about the thing stalking Jay, the teenage protagonist, comes from the person who gave it to her and who is very clearly an unreliable source for definitive information. This lack of concrete understanding serves to add another layer to the sense of dread the cinematography creates by putting the audience in the position of knowing no more about what's trying to kill her than she does, but always seeing it coming. The tension derived from that unknown heightens the stakes behind every decision her character makes, because there isn't any absolute. There is no magic incantation, no scientific wizardry, no definitive way for Jay to get free from Its pursuit. There is no solution, and we can see It coming.
When it does take on some of the tropes of so many past horror films, they are dealt with in a way that expresses the reality of this very unreal experience. Engaging to some degree in the "kids have to figure it out on their own and save the day" kind of story that was extremely popular in the eighties, It Follows leaves the territory of the heroic and delves directly into the relationships between the group of teenagers with a remarkable precision. As fantastic and unreal as a supernatural STD is, the relationships between the kids are very real, and very much filled with the kind of uncertainty that is a hallmark of the mid to late teens. In that way, the film is actually more real and more truthful than even most of the mainstream dramas that attempt to delve into the world of being a teenager.
As easy as it would be to read the film as the kind of puritanical trash so many other horror films trade on and use as currency, there are aspects of it that suggest something much more interesting is happening. There is a very real connection between what Jay experiences and the experiences of victims of rape, sexual assault or anyone who has experienced PTSD. Few films, even the more lauded mainstream "issue" films that attempt to address it, have been as good at conveying the feeling of constant danger, anxiety, and hyper vigilance that are the real power of the results of sexual assault that are most damaging in the long term. Other films may express the injustice and brutality of those experiences, but this film conveys the actual feelings, and it's easy to wonder if the title It Follows is as much about the experience following being assaulted or raped, because it certainly puts the audience more directly into that experience than most films would even begin to consider because most of them lack any real understanding. This isn't something the usual "sex gets you killed" puritanical garbage would ever attempt to portray. Those films lack any empathy for the victim. It Follows isn't begging for the audience to feel pity for Jay, it's trying to make them feel what she feels, and it does so damn well. Maika Monroe, who plays Jay, imbues the character with a combination of traits and emotions that makes her very real in this very unreal world, and is able to move fluidly from being a pro active agent for her own well being to being someone who can barely grasp the reality of their situation without ever stumbling into the territory of making that transition seem false, forced or without base. She can convey a kind of watchful distance from the other characters, then also convey an immediate, urgent need for it all to just stop and all of the emotional territory between in a way that makes Jay a very real, very human character that gives the audience the window into that very same experience. None of this seems designed as something Maika Monroe or David Robert Mitchell are making a definitive comment on so much as making them a part of the overall experience.
Time and setting are also really interesting parts of what make the film work. It is timeless, in the sense that the costuming and set design give no real sense of when the film takes place. It's as likely to be present day as it is to be some slightly alternative version of the 80's or 90's. As time is such an important factor in giving people some degree of mooring and context for the understanding and world view of characters and their environment, it just adds to a dream like quality that is at the outer edge of the films atmosphere. The only real indicator of time are some of the locations which fit directly into the rest of the film in that they could be now or thirty years ago, and then a preoccupation with urban decay as an indicator that there was a time before, that time is gone, and the present the film takes place in isn't nearly as prosperous. Being set in and outside Detroit, there's no lack of urban and suburban decay for the characters to wander through, and the sole conversation in the film that the main characters have is much more a description of their relationship to it as children than it is on the decay itself.
In conjunction with that, there are virtually no present adults in the film. Jay's mom is almost entirely absent, except to show that she is absent as a formative influence or means of support for her daughter. With those few exceptions, the perspective we're given on the adults comes from Jay and the few friends who are attempting to either help her or keep her from losing her mind, because they aren't all completely sure that what she is experiencing is actually real. Between the decay and blight of the past being so much a part of the setting and the narrative suggestion that the adults are dealing with their own demons, the time and setting become a part of conveying the sense of helplessness and hopelessness that contribute the sense of anxiety in the film. These teenagers seem doomed to a world that is in a state of constant decay and if they're parents are any indication, their future seems to be a struggle with hopelessness and decay, even without the addition of a supernatural force trying to kill one of them.
David Robert Mitchell doesn't seem to be making any kind of definitive comment about any of these weightier, heavier themes so much as meditating on them in a general way or using them as a way to make the overall impact of the experience of watching the film have more weight and resonance. What is interesting about their inclusion in the film is that they do mimic the way they work in real life. They are peripheral in the film, and in the lives of people who are experiencing them, they often seem peripheral and distant as they're going about the more urgent necessities of their daily lives, but as distant as those larger issues and ideas may seem, they are having an effect on daily life. Most of us are just trying to get through our days, and though we may be aware that our past experiences and our environment have some effect on us, it's not something we're objectively conscious of. They are things that muddle around in the backs of our minds while we're doing what needs to be done to live and survive. In that way, Mitchell has made a film whose emotional exactitude between the urgent necessity of the immediate situation at hand and the way the past and the environment influence it is pretty amazing.
It Follows isn't a standard horror film. Audience going to see it specifically because it's being hailed as "The scariest movie in a decade" are probably going to be disappointed. It's too unusual and too methodical for the majority of modern horror audiences. It's not preoccupied with telling a fairy tale story as much as it is providing a cinematic experience that recreates or instills it's characters emotions in it's audience as effectively as possible. It has much more in common with The Shining than it does with The Haunted, and even though The Shining is now consider a classic, must see of the horror cannon, it's less linear approach will have much less mass appeal. It's interesting, effective film making with more attention to emotional detail than to hitting the requisite plot points and it creates an incredibly effective atmosphere of dread that will be a welcome departure for more discerning film and horror buffs.