Babylon 5 was a show that should never have been commissioned. Five seasons of the United Nations set in space, anyone? Well, set your phasers to stunned because while Star Trek gets all the glory – what with its big-name actors, great special effects and lasting cultural cachet – it was Babylon 5 that became every true sci-fi fan’s secret favourite.

Set against a clandestine war between the villainous Shadows and the supposedly angelic Vorlons to determine the fate of the universe, aliens and humans came together to fight for their own destinies. Babylon 5, a five-mile-long space station, was just the backdrop for a galaxy of unexpectedly emotional storylines where flawed characters – including a gruff orange alien called G’Kar – found redemption. You forgave the PlayStation 1 special effects (it ran from 1993 to 1999) and sometimes laughable makeup for a single heart-rending soliloquy. Of course there were silly moments, such as when a character crawled inside a chrysalis and left you wondering if you were about to see the first alien-butterfly hybrid on TV, but the emotional payoff of bizarre events like this made Babylon 5 unmissable. In fact, the character in the chrysalis, Delenn, went on to become half of one of the best love stories ever told in science fiction.

Babylon 5 was, as the introduction of the show told us, the “last, best hope for peace”. It was also, at the time, the last, best hope for TV. Before J Michael Straczynski’s creation, sci-fi shows had mostly focused on “monster of the week” formats where some wacky alien (mostly human-shaped but with an oddly mangled forehead) turned up and wreaked havoc. Here was a show pitched as something different: a five-year story arc that would be told week after week. Trusting an audience to keep up in this way was as out-there as flying saucers or Centauri tentacular penises. Babylon 5, however, became a cult favourite that paved the way for shows such as Lost and Game of Thrones; ones that promised a clearly planned story told over years, but that unfortunately also ended up delivering a shambles of a final season.

Messing with temporal matters is usually fatal in science fiction but here the show itself simply ran out of time. During the fourth season the future of Babylon 5 was thrown into doubt by the axing of the network that hosted it. So, to give the fans the closure they had earned, major plot points were tied up neatly in the last few episodes of a tightly packed “final” season.

Unexpectedly, however, the show was renewed, but by that point the plasma tanks were running on empty. All the plotlines were used up. Fans who stuck with it to the end were treated to one of the most emotional show finales ever, but even that was tinged with disappointment as it had originally been filmed for the fourth season. With the big bad species the Shadows defeated in season four a new, less powerful, threat was introduced in the form of a servant race who described themselves as “a shadow of a shadow”. They might as well have been describing the show’s limp send-off.