Each story centred around a group of teenagers who aid a British security agent to thwart the plans of a villain and avert an international disaster.
Each of the eight series comprised 13 x 30 minute episodes divided into two or three linked stories.
For extant episodes, the episode title and the names of director and writer are taken from the programme credits[1] (except in the case of Chris McMaster who did not take a director credit).
[6][7] Air dates are from TV listings for the earliest broadcast, some ITV regions may have been later.
53 of the 104 episodes exist: 27 as broadcast masters, 14 as telerecordings and 12 in domestic formats (e.g. VHS).