The best way to understand Sapphire & Steel is to imagine being asked to make a mass-market Science Fiction show entirely in a studio with a budget of $300.
The show is an amazing example of what can be accomplished with intelligent writing, limited production technology and a tiny budget. The second episode contains an amazing scene of some WWII submariners suffocating to death, entirely made from acting, lighting and camera angles. That’s pretty much how the show at its best works: through excellent acting and photography (despite the low quality video) we are made to believe in things that really don’t sound very convincing when described.
The show is at its worst when the acting or writing flags. The central duo played by Joanna Lumley and David MaCallum never really fail us but a number of installments are marred by poor supporting acting.
The writing is for the most part quite strong, however, it must be said that part of the charm of the show is part of the weakness of the show: the writers don’t give a fig about explanations or network-notes and often take several episodes (the show is comprised of multi-episode serials, as was common at the time) to make clear exactly what is happening.
On two occasions, though, the writing lets us down. The serial about the visitors from the future is all over the map and very much of its time and the one about the fancy dress party episode, while quite amusing, loses what comes to be the shows trademark claustrophobia and surreal horror. It also suffers from an implausible love triangle. (The serials have no titles.)
As was common in British TV writing at the time, the scripts do suffer from some padding. Though not nearly so much padding as so often plagued its cross-network rival, Doctor Who. A typical serial will start with something strange happening, usually triggered by the presence of anachronistic elements: old objects mixed in with new. Time, treated by the series as almost some kind of active malignant, Lovecraftian force, breaks out of its constraints. Then Sapphire and Steel arrive to clean up the mess. Usually they succeed with great difficulty and only a partial victory.
The duo are some sort of only cryptically explained interdimensional detectives; though virtually nothing is revealed of their backstory, they are full-fleshed and have a electrifying chemistry. Sapphire is armed with several abilities: chiefly the power to rewind time for up to 24 hours to see what happened, or on occasion visit, and various forms of clairvoyance. Steel is telekinetic and can freeze the menacing projections of Time. Both communicate telepathically, as do the other operatives we meet, Lead and Silver.
The best serial is the second one. The worst is actually the first! It’s quite clear that the show was conceived as “just for kiddies” but somewhere after mounting the first story a dramatic change in creative direction occurred. The first story is creepy and a bit surreal but nothing more. But the second serial is where the show really comes into its own. In fact its so good and so unusual that it deserves to be treated on its own, something this space does not permit.
If you want nice special effects, a through-composed pseudo-orchestral score and stroboscopic editing you will not like this show. If you want everything explained with no loose ends and a story arc and a catchprase and a hammy dude with sunglasses, you will not like this show. If you like atmosphere and mystery and imagination you will like this show. If you like theater and characters and to take your time exploring a world revealed in hints and implications, you will like this show. A cult classic.