After working as the script editor for The View From Daniel Pike (1971), Sutherland's Law (1973), Barlow at Large (1975) and Z-Cars (1975–1976), he was encouraged by Bill Slater, then BBC Head of Serials, to move to production.
Under Philip Hinchcliffe, the series had "reached an almost unprecedented level of popularity",[1] but also come under heavy criticism for its frightening and violent content, especially from Mary Whitehouse.
[8] Williams also wrote significant portions of the scripts for two stories beset by writing problems, The Invasion of Time (1978) and City of Death (1979).
[2] Although the viewing figures dipped somewhat during Williams' first two seasons, they remained healthy and in 1979 the series achieved its highest ever ratings of 16.1 million viewers (for episode 4 of City of Death), although this was partly attributable to the strike which took the BBC's then-only rival, ITV, off the air.
Released as part of The Collection: Season 15 Blu-ray box set, it features interviews with family, close friends and colleagues, and publicly confirmed that his death was a result of suicide.