The episode plots are largely thrillers, similar to each other in that characters in each episode have someone or something to fear. The series usually did not explore supernatural territory apart from episode four. The main focus remained on down-to-earth fears of a psychological type.
History
Very little has been recorded of the series' productionhistory. Eleven episodes were produced; they were aired over a period of about two-and-a-half years. The first episode, broadcast in 1970, was followed by a season of nine episodes in early 1971. The final episode was broadcast nearly two years later in 1973. The series aired only once and was never repeated, until the autumn of 2019 when it began being shown on Talking Pictures TV.