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.

Eleven episodes were produced; they were aired over a period of about two-and-a-half years.

The final episode (thirty minutes long, rather than sixty) 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.