The film stars Joel Fry, Reece Shearsmith, Hayley Squires, Ellora Torchia, John Hollingworth, and Mark Monero.

The outpost is located in an unusually fertile forested area outside Bristol to help in the studies and experiments of his former colleague and ex-lover Olivia Wendle regarding using mycorrhiza to increase crop efficiency.

The next night, Martin discovers a rash on his arm before he and Alma are assaulted by unknown assailants who also raid their camp, destroy their equipment, steal their shoes, and loot some of their supplies.

That night, the mist continues to close in on the site as Zach arrives, telling them to communicate with the standing stone using the sounds and lights as well as to consume a "sacrament," a mixture of ground mushrooms alluded to in the book.

[6][7] In November 2020, it was announced that the cast included Joel Fry, Ellora Torchia, Hayley Squires and Reece Shearsmith, and that Neon was set to distribute in the United States.

[11] Peter Bradshaw of The Guardian gave the film a score of 4/5 stars, writing that it "brings us back to Wheatley’s classic world of occult loopy weirdness and cult Britmovie seediness, with a new topical dimension of pandemic paranoia".

[12] Mark Kermode also gave the film a score of 4/5 stars in his review for The Observer, saying that it "combines humour and horror in terrifically bamboozling fashion, not least during a gruellingly extended amputation sequence that will have you squirming, laughing and wincing all at once.

"[13] Linda Marric of The Jewish Chronicle also gave the film a score of 4/5 stars, describing it as "a brilliantly imagined, well acted and thoroughly compelling offering from a writer-director who is a cut above the rest when it comes to small scale horror productions.

"[16] Barry Hertz of The Globe and Mail wrote: "While I hope to never, ever watch In the Earth again, I must admit to admiring parts of it, too", and praised the film's use of dark humour.

[17] Matt Zoller Seitz of RogerEbert.com gave the film a score of 3/4 stars, writing: "Even though some sections feel rushed and it falls apart at the end, every part of it is memorable.

"[19] Randy Myers of The Mercury News gave the film a score of 2/4 stars, writing: "While it lacks the thematic punch of [Ben Wheatley's] High Rise, Earth deserves points for originality, but grows wobbly by its end.

"[20] Kevin Maher of The Times gave the film a score of 2/5 stars, describing it as ending with "a prolonged blast of rapid-fire psychedelia that seemed like an outrageous narrative cop out.