This article contains spoilers for “Wolf Man.”

Aging is the ultimate body horror, as it’s the long, slow road toward death that every living thing must experience, bar none. This process, as with most body horror, is primarily expressed physically. After all, most people will say that they’re mentally as young as they ever were, while they’re observing how their body is having issues performing the way that it used to; it’s highly common to see a social media post by a 30-something person lamenting their newfound back issues or some such ailment. A person’s perception of time passing may make it seem like the years have gone by in a flash, but the slow process of aging allows most people to make the physical transition easier, as it happens nearly imperceptibly.

Yet that perception is drastically challenged when something occurs to change our status quo. In my own experience, I used to roll my eyes at those social media posts about people experiencing the onset of various aches and pains, erroneously believing I hadn’t experienced such things. The truth was, I have, and still do — my chronic health issues (including but not limited to a liver transplant) changed the way I see and interact with the world from an unusually young age. I can no longer relate to such “relatable” content because I no longer see the same world most people do.

Leigh Whannell’s “Wolf Man” is a movie suffused with themes of body horror, illness, transformation, perception, and, ultimately, death, telling the tale of poor Blake Lovell (Christopher Abbott) becoming infected with a “hills fever” which may or may not be supernatural. Blake’s ordeal is condensed into one long, harrowing night, during which his wife Charlotte (Julia Garner) and daughter Ginger (Matilda Firth) helplessly watch him transform into an inhuman creature. While the film contains most of the prerequisite elements of a body horror transformation horror movie, it does one thing that no other body horror movie, let alone a werewolf movie, has attempted on the same scale before: it shows us what it’s like for Blake to undergo this change mentally and emotionally as well as physically. This angle is not only part and parcel of Whannell’s interests as a filmmaker, but it makes “Wolf Man” a uniquely terrifying and tragic experience.

For the October 4, 1985 episode of “The Twilight Zone” revival series, Wes Craven directed a segment entitled “Wordplay,” written by Rockne S. O’Bannon. In it, an average salesman inexplicably begins hearing odd words in place of others, and soon enough everyone around him has begun to speak a completely different language. The story is a fantastic metaphor for the feeling of being out of phase with everyone around you and emphasizes the isolating horror of being unable to understand or be understood. The segment closes with some hope for the character, making the story a parable for those who must learn to live with some form of disability.

“Wolf Man” takes this concept further into horrific territory, showing that the infection Blake suffers from ensures that there will be no coping or learning mechanism to allow him to continue to co-exist with humans. As the disease remakes Blake’s body, enhancing some of his senses like his sight and hearing, his ability to speak disappears. At the same time, he’s no longer able to understand his wife and daughter, leading to worry and frustration on both sides. Part of the problem is that Blake, Charlotte, and Ginger were already having communication issues even before Blake got scratched by a werewolf, with Whannell and co-writer Corbett Tuck using the couple’s marital problems and their separate issues with raising their daughter as evidence for how tenuous our ability to communicate with other people is even when all our faculties are available to us. The tragic grace note regarding this theme comes when Blake, who used to be a writer, makes one last attempt to communicate with his wife by writing on a pad of paper. He writes “dying,” trying to describe his current state, and Charlotte refutes this (for his sake as well as her own denial), reassuring him he’s just sick. Even when words are still available to them, the couple can’t come together.

George Waggner and Curt Siodmak’s “The Wolf Man,” which Whannell’s film is named after and inspired by, fully established the werewolf as a tragic figure, following Stuart Walker’s “Werewolf of London” made six years earlier. This tone comes from the fact that the werewolf is a cursed figure, a being forced to either live a dual life or have a dual personality, depending on the interpretation. Throughout the many werewolf films made after these first two Universal Pictures entries (to say nothing of TV shows, books, and other media), artists have typically given the werewolf some minor respite from their plight. This usually occurs in the form of some kind of euphoria after their transformation and can be seen in films as diverse as “An American Werewolf in London,” “The Howling,” “Wolf,” and “Ginger Snaps” (the latter also being a film about a slow, permanent transformation rather than a magical, back-and-forth one). Even David Cronenberg’s remake of “The Fly,” the film which hews closest to the brand of body horror in “Wolf Man,” sees its titular creature enjoy a period of virility before his degeneration.

In contrast, Whannell’s “Wolf Man” isn’t granted any such perks. Instead, the film commits almost totally to its conception of the werewolf curse as a natural disease, following in the footsteps of “The Fly.” Yet it even goes a little further into sci-fi territory than that movie did, at least in the way it depicts Blake as becoming something fully non-human rather than a hybrid of human and animal. In the way Blake gradually finds himself separated from the human world around him in every way possible, his transformation isn’t just akin to Larry Talbot or Seth Brundle but is also analogous to astronaut Dave Bowman (from “2001: A Space Odyssey”) and Lucy (from “Lucy”), characters who have their humanity and identity broken down thoroughly enough in order fully become an entirely new being. Where such transformations in sci-fi films like those can be seen as more transcendent than tragic, Whannell applies the concept to a horror lens, emphasizing how such total loss of one’s humanity could be as frightening as it is freeing.

All of Leigh Whannell’s films, whether as a screenwriter or a director, concern the theme of perception. This is typically due to the fact that most of Whannell’s scripts involve a narrative twist, and these twists tend to be about things that a protagonist (and, thus, the audience) is either seeing or not seeing until it’s too late. The twist in “Wolf Man” isn’t narrative, but structural. Whannell presents dueling perspectives — the world outside of Blake versus the one within — which, in effect, allows for a dual transformation to occur. Blake, in the real world, is transforming into a wolf creature before Charlotte and Ginger’s eyes, while Charlotte and Ginger are transforming into some sort of wraith-like demons in Blake’s eyes.

This perspective shift, especially when added to the communication breakdown Blake suffers from, fully articulates what it might be like to experience transforming into a werewolf. It’s not that Blake begins to have the thoughts and instincts of an animal, but rather that his human personality is so completely changed by the distorted information that his senses are feeding him. Like a person caught in Jigsaw’s trap from “Saw,” like someone stranded in the Further from “Insidious,” or like someone at the mercy of an abuser (whether it’s an AI program like STEM in “Upgrade” or a vicious and powerful ex in “The Invisible Man”), Blake’s reality is being dictated to him by the werewolf disease.

In addition to this perspective shift amping up the terror and tragedy of the werewolf character, it also fully realizes the dissonance inherent in the Wolf Man character. He, or she, or it, is a being caught between two worlds while belonging to neither, a Lovecraftian Thing That Should Not Be, to borrow a song title from Metallica. It’s easy to pity, or even laugh at, the werewolf, eternal schmuck of horror cinema. It’s a little less easy once you realize that we all go through our own irreversible, cursed transformation, sooner or later. As Whannell’s film says, dying happens to everybody; the trick is in how you respond to that change.

“Wolf Man” is in theaters everywhere.