‘In the Earth’ Theories, Meaning, Explanation, and Themes

I do love a good man vs. nature but nature is f*cked up on acid the whole time. Which sounds silly, I know, but if you’re honest with yourself, it’s become something of a horror subgenre.

If I’m right about that subgenre existing, In the Earth is its quintessential film. And I love it for that.

I took some time to give this one a second viewing so I could write about it here. So, here’s my analysis of In the Earth.

Screenshot from “In the Earth” trailer.

Top Theories About the Meaning and Themes of ‘In the Earth’ (2021)

1. Nature as a Conscious Force

Theory: The film presents the forest (through the fungal networks and the standing stone) as a sentient, ancient intelligence that transcends human understanding. Olivia and Zach represent two opposing ways of engaging with this force: scientific experimentation versus mystical reverence.

• Why It Fits:
  • The mycorrhizal networks are depicted not only as scientific curiosities but as gateways to something greater. Both characters become consumed by their desire to commune with this intelligence, ultimately at the cost of human life and sanity. 
• Key Moments:
  • Zach’s rituals and stitched symbol on Martin’s arm, marking him for the forest’s attention.
  • Olivia’s sound-and-light experiments designed to “speak” to the stone.
  • Alma’s final distorted voice, as though the forest has taken her as its vessel.

2. The Pandemic as a Metaphor for Human Fragility

Theory: The pandemic backdrop is not just a setting but a mirror: as the world outside is ravaged by an invisible pathogen, the characters enter a forest ruled by fungal spores—another form of invasive infection that reveals humanity’s vulnerability. The story suggests that humans are never fully in control, always at the mercy of forces too small or too vast to contain.

• Why It Fits:
  • Both Martin’s infected wound and Alma’s hallucinatory experience inside the hazmat suit echo the pandemic, emphasizing that no barrier—scientific or technological—can fully insulate us from nature’s reach.
• Key Moments:
  • Martin’s foot infection spiraling out of control, despite modern medicine.
  • The mist of fungal spores infiltrating Alma’s protective suit.
  • The collapse of the supposed safe “government” outpost into something helpless against larger forces.

3. The Destructive Power of Obsession

Theory: Olivia and Zach embody how obsession—whether scientific or mystical—corrupts. Both are willing to sacrifice others in their pursuit of communion with the entity. Martin, caught between them, represents how obsession can draw in and consume even outsiders who stumble into its orbit.

• Why It Fits:
  • Each character prioritizes their pursuit of the entity over morality, safety, or human connection. The “sacrament” and the gruesome experiments are symbols of obsession driving people to ritualized madness.
• Key Moments:
  • Olivia’s refusal to abandon her research, despite clear danger.
  • Zach’s drugging and mutilating of Martin in his zeal.
  • The shrine-like tent filled with photographs of past victims, showing how obsession leaves only destruction.

4. Myth, Folklore, and the Human Need for Story

Theory: The legend of Parnag Fegg symbolizes humanity’s tendency to create stories to explain the inexplicable. Zach interprets the forest’s power through folklore, Olivia through science, and Alma through survival instincts. The film suggests that all these frameworks are inadequate but reveal more about human psychology than about the forest itself.

• Why It Fits:
  • The characters don’t experience a single, objective truth—rather, their interactions with the forest reflect their chosen interpretive lenses. The entity itself remains elusive, reinforcing the idea that humans craft meaning rather than uncover it.
• Key Moments:
  • Zach’s talk of an ancient sorcerer placing his essence in the stone.
  • Olivia’s invocation of ancient books mixed with her soundboard experiments.
  • Alma’s final role as a kind of guide, her distorted voice echoing mythic transformation.

5. The Forest as a Stage for Human Violence

Theory: The supernatural may be less important than the way humans project violence and madness into the forest. The “entity” becomes an excuse—whether through myth or science—for characters to justify horrific acts. The true horror lies not in the forest’s power, but in humanity’s.

• Why It Fits:
  • Every death, mutilation, or betrayal in the film comes from human hands, not the forest itself. The “visions” may be drug-induced or psychological responses to trauma. The forest is a blank canvas onto which characters project their fears and obsessions.
• Key Moments:
  • Zach’s mutilation of Martin, done not by mystical force but by his own hands.
  • Olivia’s staged photographs of victims, an act of human cruelty framed as “research.”
  • Alma’s killing of Zach—a violent necessity, but still another human act in the cycle of bloodshed.

Key Themes in ‘In the Earth’

Survival in Hostile Environments

The film highlights the fragility of the human body and mind when confronted with the elements. From Martin’s injury spiraling into infection to the characters’ dependence on makeshift shelters and scarce supplies, survival is shown as precarious, hinging on resilience and adaptation in a world that refuses to yield.

Trust and Betrayal

Encounters in the forest repeatedly force the characters to question whom they can rely on. Zach initially appears helpful but turns violent; Olivia seems like a rescuer but manipulates in her own way. The theme underscores the danger of misplaced trust when isolation magnifies vulnerability.

Science vs. Mysticism

While not about interpreting the entity itself, the film stages a clash between rational experimentation and ritualistic belief. Olivia embodies technological faith in data and machines, while Zach relies on folklore and ritual. Their rivalry reveals how humans impose competing worldviews onto the unknown.

Isolation and Madness

Cut off from the outside world and immersed in the forest’s oppressive atmosphere, the characters descend into psychological instability. Isolation erodes reason, making them more susceptible to hallucinations, manipulation, and violence, suggesting that madness is as much a product of solitude as of supernatural forces.

Human Exploitation of Nature

The story quietly critiques humanity’s impulse to extract, manipulate, or weaponize the natural world. The government’s interest in crop efficiency, Olivia’s experiments, and Zach’s rituals all reflect different ways humans try to bend nature to their will—often at catastrophic personal cost.

Plot Summary

• Year Released: 2021
• Director: Ben Wheatley
• Writer: Ben Wheatley

In the Earth (2021) follows Martin, a scientist traveling with guide Alma to a remote research site in a forest during a pandemic. Along the way, they encounter Zach, a hermit who drugs, mutilates, and terrorizes them with rituals tied to a local woodland spirit. They eventually reach Olivia, Martin’s former colleague, who is conducting experiments to communicate with a mysterious force connected to the forest’s fungal networks. As spores and visions overwhelm the group, the boundaries between science, folklore, and madness blur. By the end, Alma, Olivia, and Martin are transformed by their encounter with the forest’s inexplicable power.

Movies Like ‘In the Earth’

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The Ritual (2017)

A group of friends hiking in a Scandinavian forest encounter an ancient presence tied to local mythology, testing their sanity and survival.

Annihilation (2018)

Scientists exploring a strange zone overtaken by an alien force face body horror, ecological transformation, and the limits of human understanding.

—> Watch Annihilation online.

The Wicker Man (1973)

A police sergeant investigates a remote island community steeped in pagan ritual, where faith and folklore conceal darker truths.

—> Watch The Wicker Man online.

The Blair Witch Project (1999)

Found-footage chronicling filmmakers lost in the woods, where legend and paranoia intertwine to erode their grip on reality.

—> Watch The Blair Witch Project online.

The Beach House (2019)

A couple on a seaside vacation face a mysterious, spore-like ecological phenomenon that dissolves boundaries between body and environment.

—> Watch The Beach House online.

The Hallow (2015)

An environmentalist and his family in rural Ireland are stalked by creatures from folklore after disturbing an ancient forest.

—> Watch The Hallow online.

Color Out of Space (2019)

A meteorite crash disrupts a family farm, as alien contamination transforms the land and people in grotesque, psychedelic ways.

—> Watch Color Out of Space online.

Have Your Own ‘In the Earth’ Theory?

I don’t mean to belittle this movie with my jokes about the acid-loving nature subgenre. I really think this was an excellent horror film with a lot to say.

Do you agree? Anything to add?

Let me know your thoughts and theories about In the Earth in the comments.

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