First broadcast 10th July 1979.

A pair of inter-dimensional operatives, Sapphire and Steel are two of multiple elements that assume human form and are sent to investigate strange events, where they appear to be engaged in guarding the continuing flow of time.
On an ordinary evening, a mother and father sing nursery rhymes to their daughter Helen before bed. Their teenage son Robert becomes alarmed when all the clocks in the house stop working.

David McCallum ... Steel
Joanna Lumley ... Sapphire
Steven O'Shea ... Robert Jardine
Tamasin Bridge ... Helen Jardine
Felicity Harrison ... Mother
John Golightly ... Father
Ronald Goodale ... Countryman
Charles Pemberton ... Policeman