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 and Steel have been assigned.

Sapphire & Steel was originally created as a children’s series, something which is most evident in the opening story, as two children, Rob (Steven O’Shea) and Helen (Tamasin Bridge), are the people in need of help from the mysterious “time detectives”.

Production limitations (an incredibly low budget) helped to shape the tone of all S&S‘s serials.  Small casts (with usually only a handful of main speaking roles), a handful of sets (only one of the six serials featured any location filming) and very limited special effects tended to be the order of the day.

The unsettling feel of this opening story is quickly established.  The location is a large, comfortable and old-fashioned house.  Whilst Rob is downstairs doing his homework, his mother and father are upstairs, reading nursery rhymes to their young daughter Helen.

The snatches of nursery rhymes used as incidental music is an indicator that the rhymes are designed to have a sinister, rather than comforting, air.  The feeling of unease can also be seen on Rob’s face downstairs – he doesn’t know why he feels his way, he just does.

The fact that we don’t see the faces of Rob and Helen’s parents is a deliberate move, it helps to make their brief appearance another discordant element.  When they vanish – after reading a nursery rhyme – Robert attempts to take charge (phoning for the police) although his constant reassurances to Helen that everything will be all right seems to be as much for his benefit as hers.

Shaun O’Riordan’s direction has a few notable moments, especially a long tracking shot – which moves from Helen, alone and frightened in the kitchen, down the corridor and to the front door.

The events so far have primed us for the arrival of Sapphire (Joanna Lumley) and Steel (David McCallum) and their first appearance is a memorable one.  They adopt patterns of behaviour which will become familiar – Steel is brusque and business-like, whilst Sapphire is friendly and amusing.

The mystery of their arrival, as well as the fact that Steel knows Rob’s full name, is never answered – rightly so, since part of the tone of S&S depends on the fact that the title characters are inscrutable and unknowable.  But although Steel regards the presence of Rob and Helen as little more than an irritation, Sapphire attempts to explain what’s happened and why they’re here.

There is a corridor and the corridor is time. It surrounds all things and it passes through all things. Oh you can’t see it. Only sometimes, and it’s dangerous. You cannot enter into time, but sometimes … time can try to enter into the present. Break in. Burst through and take things. Take people. The corridor is very strong; it has to be. But sometimes, in some places, it becomes weakened. Like fabric, worn fabric. And when there is pressure put upon the fabric….

Sapphire is rather more playful and frivolous in this episode than she’d later become. She changes dresses and hairstyles in the wink of an eye several times, something which impresses Rob no end (who’s already a little in love with her).  But Steel’s on hand to bring the conversation down, telling Rob about the dangers in the house. “There are things – creatures, if you like – from the very beginnings of time, and the very end of time. And these creatures have access to the corridor. They’re forever… moving along it. Searching… looking… trying to find a way in. They’re always searching, always looking …”