In the Mouth of Madness, the finale of John Carpenter's unofficial ‘Apocalypse' trilogy, must have been massively anticipated upon release, tasked with filling the boots of such staggering predecessors as The Thing and Prince of Darkness. Whether it met those lofty expectations or not will vary from person to person, but Carpenter certainly didn't hold any punches when it came to concluding his trilogy.

This strange, complex film introduces its leading character, John Trent (Sam Neill), as he is checked into a mental institution, fighting for his freedom to no avail. When a psychiatrist arrives to evaluate him, the film takes the audience back to what led Trent to his cell – could he be hiding there rather than genuinely mentally ill? This neat framing device quickly moves on to portray how his life was before it was transformed by unspeakable horror. Trent is an insurance fraud investigator and cynic who expects nothing but the worst from people. He is excellent at his job and genuinely enjoys it, which makes it unsurprising when he takes on the challenging case of missing horror writer Sutter Cane, thought to have intentionally ‘gone missing' in a PR stunt to promote his newest novel. Cane is so successful that his rabid fanbase has claimed that reading his works has had severe psychological impacts upon them, and a number of them claim that Cane's writing is even prophetic. Trent predictably scoffs at this before beginning his investigation.

He quickly finds himself in the thought-to-be fictional town of Hobb's End alongside Cane's editor, Linda Styles (Julia Carmen). And it is here that Carpenter begins to work through the film's key themes and ramps up the scares with some creepy imagery and early pangs of the uneasy feeling that reality and fiction are blurring into one. The duo's time in Hobb's End may not provide them with many tangible, practical answers, but the increasingly intense horrors which they encounter certainly suggest that there is some truth to the hysteria surrounding Sutter Cane's work.

This emerging horror reveals itself in scarred children and, more disturbingly, through dialogue from one man who tells an already overwhelmed Trent that he must leave town to avoid being impacted by something infecting the minds of the locals and removing their free will (forcing them to act in the way that Cane has written for them in his latest novel).

As the film continues, it becomes more chaotic and unpredictable. Trent, whose cynicism initially seemed like a shield from the mental tortures the other characters are experiencing, begins to succumb to this inexplicable sense of pervading doom and loses his grip upon reality as the Lovecraftian nature of the story reveals itself in the stunning special effects which bring horrifying monsters to life, tentacles and all.

The blend of a procedural mystery and apocalyptic horror is masterly from screenwriter Michael De Luca, as is the writer's interest in the power of art upon its audiences. However, it is not only Carpenter and De Luca who contribute quality work to this film. Sam Neill is particularly brilliant, channelling just enough seriousness balanced with memorable over-the-top antics, similar to his turn in Andrzej Zulawski's classic horror film Possession.

The film's creature designs are delightfully gnarly and creatively inspired, and the sound design accompanying them undeniably adds to their overall effect, as well as creating an absorbing atmosphere which makes the film's more hallucinatory moments feel much more involving. Its aesthetic, consisting of long-ish takes and wide-angle tracking shots, also becomes increasingly unkempt as the film continues, matching the growing absurdity and intensity of the plot. In this way, the film's technical elements feel infused with its story, guiding the viewer through the bizarre story with patience that is well rewarded by the freakish rush in the third act.

This relentlessly paced horror mystery is one of John Carpenter's finest films. Its frequent twists and turns ensure that the audience experiences the same psychological whiplash as the characters do, putting them through the wringer for 100 crazy minutes and proving Carpenter's genuine mastery over the horror genre. A minority may be frustrated by the lack of clarity and answers, but what Carpenter isn't willing to give in explanation, he is willing to give in gripping thrills and thoughtful, philosophical ideas.

4K Ultra HD Blu-ray Limited Edition Special Features

Brand new 4K restoration from the original 35mm camera negative by Arrow Films
4K (2160p) Ultra HD Blu-ray presentation in Dolby Vision (HDR10 compatible)
Original lossless DTS-HD MA 5.1 and stereo 2.0 audio options
Optional English subtitles for the deaf and hard of hearing
Archive audio commentary with director John Carpenter and producer Sandy King Carpenter
Archive audio commentary with director John Carpenter and director of photography Gary B. Kibbe
Brand new audio commentary by filmmakers Rebekah McKendry & Elric Kane, co-hosts of Colors of the Dark podcast
Making Madness, a newly filmed interview with producer Sandy King Carpenter
Do You Read Sutter Cane?, a newly filmed interview with actor Jürgen Prochnow
The Whisperer of the Dark, an archive interview with actress Julie Carmen
Greg Nicotero's Things in the Basement, an archive interview with special effects artist Greg Nicotero
We Are What He Writes, a new featurette in praise of John Carpenter and In the Mouth of Madness
Reality Is Not What It Used To Be, a new appreciation by film scholar Alexandra Heller-Nicholas
Horror's Hallowed Grounds, an archive featurette looking at the locations used in the film
Home Movies From Hobb's End, behind-the-scenes footage
The Making of In the Mouth of Madness, a vintage featurette
Theatrical trailer and TV spots
Reversible sleeve featuring original and newly commissioned artwork by Francesco Francavilla
Double-sided fold-out poster featuring original and newly commissioned artwork by Francesco Francavilla
Perfect bound collector's book featuring new writing on the film by Guy Adams, Josh Hurtado, Richard Kadrey, George Daniel Lea, Willow Catelyn Maclay, and Alexandra West