The documentary features retrospective interviews with the lead actors and creative crew behind Sapphire & Steel. The participants discuss their experiences working on the cult-classic 1979–1982 television show, sharing behind-the-scenes memories, insights into the unique atmosphere of the series, and recollections about the production of the mysterious, time-defying extratemporal agents
| Actor | Role |
|---|---|
 David McCallumHimself | Himself |
 Joanna LumleyHerself | Herself |
 Shaun O'RiordanHimself | Himself |
| PPeter J. HammondHimself | Himself |