A sense of unease and fascination permeates this film above all else—it’s remarkably smart. During construction work at a new underground railway station, laborers discover an unusual artifact. Professor Quatermass is brought in to investigate and determines that the object has its roots on Mars. Initially met with skepticism, it gradually becomes clear that Martians have previously interacted with humanity, and now they've been reawakened. This represents the third Hammer film based on Nigel Kneale’s BBC-TV Quatermass series, following The Quatermass Experiment and Quatermass 2. However, in my opinion, this one stands out as the strongest of the three. What truly succeeds here is the skillful blending of suspense and intellect—a pervasive feeling of foreboding that's balanced by a desire to understand what’s transpired, and more importantly, what will occur next. The narrative unfolds expertly thanks to Roy Ward Baker’s carefully controlled direction; Quatermass And The Pit compels you to focus on every nuance, with each discussion contributing to this captivating story. Then there is the ending which delivers significantly—to describe it would spoil the film's resolution, and that would be a mistake. Watch it because it ranks among the finest science fiction films of the 1960s, an essential viewing experience for fans who appreciate some substance alongside their genre thrills. 8.5/10

Source on TMDB