In the same way big screen versions of stage musicals used to have professional vocalists “singing” the parts of the lead actors, so it might be advisable to have professional scribes employed to “write” the scripts of Russell T Davies.

Sure, the man has killer ideas, dramatic vision and a flair for neat casting, but rarely can he put decent sounding words into the mouths of his characters. It was true for Doctor Who, as it was for Queer as Folk, as it was for Bob and Rose and so it proved again in the first episode of Torchwood. He just seems to have precious little ear for dialogue and almost no flair for what every decent adventure series needs: witty bon mots and wry pay-offs.

Instead this ultra-important, desperately crucial flagship debut for BBC3′s biggest ever TV serial resounded to the likes of, “Walked here – I bloody walked!”, “That’s just a pterodactyl,” “I’d like to see CSI Cardiff!”. And perhaps worse of all, the exchange between the previously unimpeachable Captain Jack Harkness and the newly-enlisted Gwen Cooper: “I can’t die.” “Okay”. “But I can’t.”

One bunch of people who will be unequivocally happy with the first episode of Torchwood, however, is the Welsh Tourist Board. Whenever Davies ran out of thunderously banal one-liners and unfunny gags, he provided us with a series of, admittedly impressive, aerial shots of Cardiff. This could apparently only be bettered by aerial shots of someone standing on a tall building … looking across Cardiff.

This was a show where appearances mattered above all else, yet first impressions proved sorely wanting. Glamorous-looking rain doesn’t work for this country. It’s fine for America, but in the UK rain has to look dirty and desolate or else it just – ahem – doesn’t wash. Watching our ostensible heroes processing through a rainbow of twinkling droplets, only to then see a Welsh forensic expert cussing effusively, was like being pulled not merely between varying moods but different continents.

Here, as throughout the episode, were perfectly formed and beautifully filmed individual pieces of drama never quite managing to resolve into a jigsaw of coherently-ordered entertainment. And as proceedings continued, vignettes of emotion and fragments of speech that felt like they could function perfectly well in isolation just made no impact arranged in sequence.

So while it was exciting to see the way Gwen Cooper encountered her first alien by way of a tense advance along a corridor, it was unfortunate she had to precede this with an undignified harrumph up endless flights of dull office block stairs. And while it was thrilling to watch Captain Jack casually drug her by way of a spiked drink, it was utterly bizarre that he had to follow this with a casual stroll through a Cardiff shopping centre.

In short, your reactions as a viewer were constantly shuttled between engagement and detachment. At one point the action was pulling you in; the next pushing you away. Maybe if the characterisations had been uniformly compelling, and the characters given uniform opportunities to compel you to watch them, the episode’s scaffolding wouldn’t have appeared so uneven.

Fundamentally, the Torchwood gang didn’t really demonstrate the point of their existence. This first episode needed a potent threat or self-evident dilemma for this cosmos-tinkering youth club to get its teeth into, rather than settle for having them make their entrance by way of putting a pillowcase over the head of an alien rat.

The final scenes were the most unconvincing of all. Killing off a character that had only been on screen a total of five minutes, about whom we know little and care even less, is fine as a means to an end. When it is the end, however, and an end we’re made to think is a barnstorming jaw-dropping one (cue more flashing lights and sweeping views), you don’t just feel cheated, you feel used.

Davies has always loved instructing his audiences to read giant consequences into trivial matters, and usually gets away with it by coating such machinations in a generous layer of self-deprecation. This time, though, it was all po-faced preaching and moody stares: devices which conspired to render the dénouement even more of a trifling concern, and the viewer even more of a pawn in a rather shabbily constructed turn of events.

There was no earthly reason why Torchwood’s second in command Suzie Costello, upon being unmasked as a traitor, should promptly choose to shoot herself in the head. Given the little we knew about her, there was no unearthly reason either. It was shock for schlock’s sake. The ensuing shot of Jack and Gwen standing – yes – on top of a large building for no reason afforded no commensurate emotional release. It was just two people on top of another large building.

Overall, what began as an intriguing and subtle fish-out-of-water escapade ended in an indifferent and boring shoot-’em-up. Nowhere near enough had been done on the part of those behind and in front of the camera to convince you as to why Gwen would want to spend one second longer in the company of these self-obsessed, flash, fast-talking techno-tykes.

Contrast this with the intriguing and subtle fish-out-of-water escapade Davies provided by way of episode one of Doctor Who. At the end of those particular 45 minutes, it was entirely obvious why Rose would so desperately want to run off with a man she knew little about and embrace his lifestyle completely. There was no parallel impetus here. It felt like Gwen opted to stick around Jack and co because, well, she could. But if she suddenly changed her mind, well, there was always whathisname back home cooking up another plate of something or other. Meantime, isn’t that a nice view of Cardiff Bay?

There was an arrogant emptiness at the heart of this first episode of Torchwood which not even Russell T Davies’s relish for the disingenuous could fill. With such a high-profile proposition, generous budget and auspicious timeslot to play with, the fact he and his colleagues offered up something ultimately so lumpen was a real ungentlemanly act. Either you say what you mean or mean what you say, but at the very least you say something of substance and valour.

Perhaps it’s simply down to how much you trust Davies to treat you with respect and deliver a return on your commitment to watch. The episode title, “Everything Changes”, could have been chosen to further persuade the viewer of the degree of flux and uncertainty facing somebody who’s just discovered dead people can be brought back to life. On the other hand, it could have been chosen because it’s Davies’ favourite Take That song.

One thing cannot be another. Torchwood needs to decide between nihilistic sleuthing and camp whimsy. When it’s made the decision, the rest – including decent endings – will follow.