After two series and far too many swear words and sex jokes Torchwood has finally grown up, writes Dan Wainwright.

For an “adult” spin off of Doctor Who, the adventures of indestructible Captain Jack and co were somewhat juvenile.

It seemed as though all the episodes were written by a bunch of sci-fi nerds whose only experience of real world issues such as familiar relations were those they talked about in internet chat rooms.

Trying to give the show an edgy, gritty feel served only to dumb it down.

Attempting to follow Doctor Who’s 13-episode format with a different writer for each episode just didn’t work. With Doctor Who the title character and his sidekick would move about, meeting new characters on new planets every week.

But with Torchwood the city of Cardiff and the larger cast were vying for attention and a bit of character development that just wasn’t forthcoming.

I wish I had blogged about this last year because I distinctly remember telling my friends that the only way the show could work was if it was made into a single story arc of half a dozen episodes all written by the same person.

I remember that well because everyone turned away from me and started talking about football until I started shouting very loudly about Weevils and Time Agents and was asked to leave the pub.

Shifting the show from BBC 3 in its first year to BBC 1 for this week’s five episode bonanza has made a huge difference.

It’s as though the watchful matriarchal influence of Auntie Beeb is stronger on her main channel – like she’s supervising the kids drinking tea out of her best china instead of the disposable “stick any old tosh on it” beaker of BBC 3 – the corporation’s patronising “yoof” channel.

With Children of Earth the overall plot will probably turn out a bit disappointing – “oh dear aliens are going to invade, again, and the Doctor is nowhere to be seen”.

But sidestepping all of that we have a Gwen who has gone from gap-teethed, breathy sort of eye-candy to super tough and pregnant. Ianto is still a little wet but there’s actually some sort of a proper relationship going on with Jack that actually stands a chance of being a serious, 21st century story of same-sex love without just being the same story about sex.

So far the only good thing about Captain Jack is he spent most of episode two dead and trapped in concrete to avoid over-exposing John Barrowman but, as much as it pains me to admit, even he is coming into his own.

It’s a shame that when Torchwood nicked the idea of an unkillable captain who comes back from the dead every week from Captain Scarlet they also gave Barrowman that plastic puppet sheen. I’m also going to miss that flowing air force coat of his now it’s been blown up with half of Cardiff Bay.

If the rest of this week can keep up the suspense, and suppress the immaturity of its first two seasons, we might finally have a Torchwood worth watching.