Hammer Films have a lot to thank writer Nigel Kneale and his most popular character Bernard Quatermass for. When the BBC originally broadcast The Quatermass Experiment to a terrified audience, Hammer producer Anthony Hinds saw the potential for a movie adaptation and quickly snapped up the rights. At the time, Hammer were enjoying modest success making low-budget second features, but 1955's The Quatermass Xperiment (named so to highlight the X rating dished out by the BBFC), known as The Creeping Unknown in the U.S., became a hit and put the company's name on the cinematic map. Quatermass 2 (a.k.a. Enemy From Space) followed shortly after, and the rest is history.

It seems like they were saving the best for last, and waited a whopping 10 years to deliver it. When skeletal remains are dug up during an extension to the London Underground, Palaeontologist Dr. Mathew Roney (James Donald) is called in, who concludes that the remains are that of an ancient race of 'apemen', possibly from 5 million years ago. Bernard Quatermass (Andrew Keir) disagrees however, and when further digging reveals a large metallic object, he believes it may be of alien origin. Colonel Breen (Game of Thrones' Julian Glover) insists that it is an unexploded bomb from World War II, and refutes Quatermass' claims. As the mystery unfolds, the discovery may lead to shocking revelations regarding man's evolution, and one that we are not ready to face.

Quatermass and the Pit may feature some incredibly dated effects, but this is sci-fi as complex and intellectual as 2001: A Space Odyssey (1968); a film it is often compared to. Based on the six- part series, Pit's main issue is the difficulty in condensing hours' worth of material into a 98-minute movie, hitting the audience with one theory and revelation after another. But great sci-fi is primarily built on a singular great idea, and this is up there with the best. While the twists and turns are often a struggle to keep up with, the frantic pace created by the lack of running time means that we're kept on the edge of our seats for the duration. Keir is also an improvement on American Brian Donlevy (who played the professor in the previous two films), infusing Quatermass with warmth and a distinct Britishness.