By the early 1970s Kneale was once again regularly writing for the BBC, which announced plans to produce a fourth "Quatermass" serial in 1972. This ultimately was not made by the BBC, but Kneale's scripts were produced in 1979 as a four-part serial for Thames Television, titled "Quatermass". This time John Mills played Quatermass in an expensive and high-profile production, which was screened on the ITV network. The production company Euston Films also released a 100-minute film version titled "The Quatermass Conclusion" or "Quatermass IV", for distribution abroad. There was, however, little interest among film distributors, and it received only a limited theatrical release.