2026 marks the 70th anniversary of this suspenseful science-horror classic from legendary writer Jimmy Sangster as X the Unknown makes its worldwide premiere in 4K. Widely regarded as the missing part of the Quatermass franchise, this is the latest film to be restored by the teams at Hammer and Silver Salt Restoration.
When a soldier dies from apparent radiation poisoning, the Atomic Energy Commission sends scientist Dr. Royston (Oscar-winner Dean Jagger) to investigate. Despite extensive testing no source can be found - until a mysterious radioactive, mud-like entity resurfaces and begins claiming more victims. What do you do when the killer can’t be stopped - or even understood?
This Limited Edition comprises:
- Four discs in a stylish digipak, including 2 UHD and 2 Blu-ray, with the Hammer content duplicated across both formats.
- Three iterations of X the Unknown: the widescreen 1.66:1 UK Theatrical Version, the fullscreen 1.37:1 As-Filmed Version and the widescreen 1.85:1 US Theatrical Version.
- English, French, Italian, Spanish, German subtitles on all versions of the film.
- Brand-new 5.1 mix for 1.37:1 and 1.66:1 versions alongside the original mono film soundtrack.
- Packaged in a high-end, leather-feel slipcase.
- A rigid inner box featuring new artwork by cult favourite Robert Sammelin.
- A double sided poster of original one-sheets
- Eight art cards featuring facsimiles of the original cinema lobby cards.
Discover brand new film commentaries, documentaries, featurettes, and more. The discs feature -
- A Man on the Beach: a rare, early Hammer short film, written by Jimmy Sangster and directed by Joseph Losey (who was due to make X the Unknown).
- New commentary with actor and comedian Toby Hadoke and Nigel Kneale’s biographer Andy Murray.
- New commentary with writer/producer Dr Steve Haberman and film-maker and film historian Constantine Nasr.
- New commentary with film historian David Kalat.
- Archive 2003 commentary featuring writer Jimmy Sangster and Hammer expert Marcus Hearn.
- New commentary on A Man on the Beach by film expert Neil Sinyard.
- New documentary on the making of X the Unknown, with contributions from Toby Hadoke, Andy Murray, Wayne Kinsey, Dick Klemensen and actor Frazer Hines.
- New documentary on special effects maestro Les Bowie, with contributions from Wayne Kinsey, Dick Klemensen, Mike Tilley and archive audio contributions from Christopher Lee, Ian Scoones and others.
- A new documentary following the career of Joseph Losey - the original X the Unknown director who departed the project before shooting commenced - and his storied journey through Hollywood to Hammer films, via blacklisting and exile.
- Sidebar: X the Unknown. Film critic and writer Tim Lucas discusses X and similar films of the period with artist and film historian Stephen R. Bissette.
- Archive Jimmy Sangster interview from 2003.
- Original trailers, censor card and Super 8 cut-down version.
- Extensive image gallery of stills and publicity material.
And A 120-page booklet featuring new articles on the film's production, its relationship to the Quatermass films, cast and crew biographies, script comparisons, and more.
Special features and artwork subject to change before release date.
| Language | Mono / 5.1 / English |
| Number of discs | 2 x UHD Blu-ray, 2 x Blu-Ray |
| Region | UHD region Free, Region ABC Blu-ray |
| Certification | PG |
| Run time | Feature: 1 Hour and 20 Minutes |
| Subtitles | English, French, Italian, Spanish, German |
| Actors | Dean Jagger, Edward chapman, Leo Mckern |
| Directed By | Leslie Norman |
| Written By | Jimmy Sangster |
| Produced By | Anthony Hinds |
