The Pentyrch Incident

About the Author

Caz Clarke is a Pentyrch resident who works in security and is, by her own account and independent student-journalism profiling, the case's primary witness. She has discussed the case publicly, including as a subject of Sky HISTORY's Craig Charles: UFO Conspiracies (2022), which devoted its first episode to the case.

Gari Jones, from Merthyr, is an independent investigator with the Swansea UFO Network, a real, active Welsh UFO-research organization. He began a formal investigation of Clarke's account in October 2017, roughly twenty months after the reported event, and has separately authored a second self-published UFO book, The Denbigh Lights: A Truthful Argument For The Existence of UFOs (2022/2023), giving him an independent bibliographic footprint beyond this one case.

Historical Context & Origins

This site's own case file independently corroborates the book's central documentary claim: archived Notices to Airmen (NOTAMs) confirm that a real military exercise, named Exercise Chameleon, restricted helicopter operations without navigation lighting within a 5 nautical mile radius centered near Llantrisant on the night in question, and a second NOTAM restricted airspace for a Parachute Jump Exercise within a 10 nautical mile radius, with a drop-zone "flow cone" extending to 18,000 feet — an altitude range independent researchers, cited in the case file, argue is consistent with a High-Altitude, Low-Opening (HALO) jump typically performed only by Special Forces personnel. These are the same archived records Jones and Clarke's own FOI requests helped bring to light, and this article treats them as genuinely significant, independently verifiable evidence, regardless of which explanation for the sighting itself one ultimately favors.

The area's military geography make the exercise itself unsurprising: RAF St Athan sits roughly 15 miles south, the Brecon Beacons training grounds roughly 25 miles north, and Hereford's 22 SAS Regiment roughly 45 miles away, per this site's own case file. What the book argues is not that military activity in the area is itself anomalous, but that the specific combination of a large, structured, silently maneuvering light formation alongside that activity, followed by what the authors characterize as an inadequate and inconsistent official response to their FOI requests, adds up to deliberate concealment rather than coincidence.

This article found no mainstream South Wales or UK national press coverage of the incident from the time it reportedly occurred in February 2016; the case surfaced publicly only through Jones's 2017 investigation, the 2021 book, and the 2022 Sky HISTORY episode — a genuinely unusual gap of over five years between the reported event and any public account, which the book frames as itself circumstantial support for its cover-up thesis, and which this article notes plainly as an unusual feature of the case's evidentiary record either way.

Core Arguments & Key Concepts

Per the book's own framing and this site's case file, the central argument rests on a chain of specific claimed anomalies: aircraft flying repeated figure-eight patterns over Pentyrch for three days beforehand, the pyramid-shaped light formation itself, a green object described as ejected from the formation "as if fired from a cannon," two house-shaking explosions, and a subsequent path of large trees found snapped in Llantrisant Forest. The book presents the accumulation of these details, corroborated in part by neighboring witnesses who separately reported helicopter and fixed-wing activity, as evidence the event exceeds any single mundane explanation.

This site's own case file evaluates that same accumulated record against the Five Observables framework and concludes the case aligns most strongly with a psycho-social/misidentification hypothesis: a real, classified nighttime exercise involving low-visibility helicopters and a HALO-style parachute drop, with illumination and drop-zone marker lights, occurring at almost exactly the claimed time and place, encountered by a population with no way of knowing an exercise was underway. The case file also notes that Clarke has, in some interviews, used language closer to an interdimensional framing ("a large interdimensional craft") than a strictly extraterrestrial one — a detail it treats as a sign of an evolving, retrospectively elaborated interpretation rather than a fixed initial observation, and a caution this article extends to the book's own framing as well.

The book's argument also rests on several specific, individually checkable claims that this site's case file examined directly and could not fully corroborate: that one of the two reported explosions registered on a seismograph roughly 40 miles away, that the M4 motorway was closed in connection with the incident, and that specific aircraft types (including a C-130 Hercules and an E-3 Sentry) were positively identified overhead. The case file's own research found no citable British Geological Survey bulletin or seismologist's record matching the seismograph claim, no Traffic Wales or Highways England record of an M4 closure tied to this specific incident, and no independently verifiable flight-tracking data for the specific military aircraft types described — all resting instead on witness description passed between retellings of the case rather than on an identifiable primary record. This article follows the case file in treating these specific claims as unverified rather than either confirmed or debunked, a distinction the book itself does not always draw as sharply.

Key Cases & Evidence Discussed

This site's own Pentyrch UFO Incident case file documents the full record in far greater depth than this book review needs to repeat: the complete FOI paper trail (including the Ministry of Defence and Natural Resources Wales requests filed via WhatDoTheyKnow), the archived NOTAM evidence for Exercise Chameleon, the unverified secondary claim of a seismograph reading 40 miles away, and the inconclusive dating of the Llantrisant Forest tree damage. Readers wanting the complete, independently sourced record, including the case file's own Five Observables assessment, should consult that case file directly.

What is specific to this book is that its authors are the case's two central participants rather than outside chroniclers: Clarke as the primary witness and Jones as the investigator who spent years pursuing the FOI requests that produced the case's most concrete documentary evidence. That makes the book an invaluable primary record of the investigation's own process, alongside the corresponding caution that neither author is positioned to evaluate the evidence with full independence from their own conclusions.

Critical Reception & Controversies

As of this article's research (August 2026), the book carries a Goodreads rating of 3.80 out of 5 across 324 ratings and 24 reviews — a real, organically sized review base rather than a handful of uniform reviews typical of low-effort or content-mill titles. Reader reviews found in this research were generally positive, describing the book as well-researched and citing the weight of its FOI-based evidence, with one specific formatting criticism noted about the Kindle edition's image placement. This article found no dedicated skeptical-press or journalistic review beyond the general case coverage already documented in this site's own case file.

One detail worth flagging for anyone searching for this title: a third-party product exists on some book-cataloging sites titled "Summary of Caz Clarke & Gari Jones's the Pentyrch Incident" (a separate, unrelated study-guide-style product under a different ISBN) — this article is about the original book by Clarke and Jones themselves, not that derivative summary.

Influence & Legacy

The book's clearest legacy is procedural rather than evidentiary: it demonstrates, through its own extended FOI campaign, how much of a modern British UFO case's documentary record can be built years after the fact through persistent public-records requests rather than contemporaneous press coverage, which was entirely absent here. The 2022 Sky HISTORY episode built directly on the book's investigation, bringing the case to a national television audience five years after Jones first began looking into Clarke's account.

Set alongside this site's own case file, which weighs the same FOI-derived evidence against the archived NOTAMs' own content and concludes the exercise itself is the case's most likely explanation for the aircraft activity, this book is best read as the case's primary insider account — essential for its documentary legwork, and correspondingly best balanced against the case file's own more skeptical reading of what that legwork ultimately establishes.

The Book

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