All irregularities will be handled by the forces controlling each dimension. Transuranic heavy elements may not be used where there is life. Medium atomic weights are available: Gold, Lead, Copper, Jet, Diamond, Radium, Sapphire, Silver and Steel. Sapphire (Joanna Lumley) and Steel (David McCallum) are two detectives on a mission to safeguard the structure of Time. Not human, and hot quite alien, the mysterious couple grapple with Time, shown here as an eerie and frightening force. With uncanny powers they protect the present from invading evils of the past and future in a series of unforgettable and mysterious adventures.
Assignment IV An evil amorphous entity uses photographs to move between time dimensions. It takes over a junkshop and entraps the inhabitants. Sapphire and Steel investigate their disappearance. Assignment V A golden anniversary party unleashes Time's worst instincts. Lord Arthur Mullrine is celebrating fifty years in business but the years are rolled back and guests start being killed off. Assignment VI Sapphire and Steel meet Silver at an abandoned petrol station. They also meet several people from different decades acting suspiciously.