The original series spawned a 1972 film adaptation, released in the U.S. with the title Island of the Ghouls. A Continuity Reboot series was attempted by Channel Five in 1999, but did not elicit viewer interest past a Made-for-TV Movie aired as the pilot.
The series provides examples of the following tropes:
- Anyone Can Die: Toby at the end of "Survival Code."
- The Atoner: Quist feels lingering guilt after helping build the atomic bomb, and witnessing his wife dying from radiation poisoning.
- Hope Spot: Toby's death. Toby disarmed a nuclear bomb that had been planted at a seaside pier and, believing the threat was over, lets his wire-cutters drop into the ocean. Then he sees another wire attached to the still-active conventional explosive and...
- Killed Off for Real: Done to Toby at the end of the first series, despite being a main character.
- Quist himself in the 1999 TV pilot.
- No Celebrities Were Harmed: The episode "Sex and Violence" featured characters based on Lord Longford, Cliff Richard, and especially Mary Whitehouse, hence its Missing Episode status.
- The Plague: The debut episode "Plastic Eaters" has Quist deal with a virus that corrodes plastic materials and causes aeroplanes to fall from the sky.