ITV intended "Quatermass" to air in September 1979 as the flagship of its autumn season; advertising posters announced, "Earth's dark ancestral forces awaken to a summons from beyond the stars. The legend returns on ITV – Wednesdays at 9 pm throughout September". However, industrial action began at ITV on 3 August 1979 and escalated into a full-scale blackout from 10 August 1979, leaving the channel—and "Quatermass"—off the air for 11 weeks. Transmissions were finally restored on Wednesday, 24 October 1979, and the first episode of "Quatermass" was duly broadcast that night at 9 pm. Episode two was promoted in the "TV Times" with a full-page article by Kneale introducing the new series and looking back on the original 1950s serials, as well as a lifestyle piece with Barbara Kellerman moving house, while episode four was promoted with a full-page profile of John Mills. Ratings, averaging 11 million viewers over the four-week run, were below expectations; the serial failed to crack the top 20 programmes in the weeks it was broadcast.