So I finally got round to watching the second half of season three of Battlestar Galactica over the past few days. I approached it with some trepidation as a lot of commentators have accused the show of dipping severely in quality and even, whisper it, of jumping the shark.

And there’s no denying that compared to the electric shock of the opening arc of the third season the second half isn’t in the same class. But then, from the “good guys” using suicide bombers in 3.01 (“Occupation”) to the brutality of the treatment of collaborators in 3.05 (err… “Collaborators”) the new BSG ran a set of episodes that were as powerful as any sf I’ve ever come across. Perhaps it was a bit much to hope that they could sustain that level throughout.

Two consecutive episodes – 3.14 (“The Woman King”) and 3.15 (“A Day in the Life”) were probably the weakest and most inconsequential episodes yet aired in the new BSG – revealing that the show really can sink to the level of some of the other scifi on TV. But these episodes were bracketed by shows that demonstrate why BSG remains compulsive viewing.

3.13 (“Taking a break from all your worries”) features Baltar (Callis) being interrogated by Admiral Adama (Olmos) – it’s a fairly straightforward episode, most of BSG’s usual moral ambiguity is swept under the carpet but it is made memorable by Callis’s fantastic performance and by the resonant, terrifying voice of Olmos in the interrogation sessions.

Episode 3.16 (“Dirty Hands”), meanwhile, is memorable because it is one of those episodes that tackles an issue that only BSG would tackle in terms of an sf drama and a topic that almost no ongoing dramas would ever address – industrial unrest. It takes us aboard one of the fleet’s “invisible ships” the “tylium refinery” Hetei Kan – where workers are toiling day and night in horrible conditions to deliver the fuel the fleet needs to survive. When the workers begin to organise for a better deal and fairer treatment the first reactions of Adama and Roslin are dictatorial and repressive. Actions which give Baltar’s subversive agenda of splitting the “proletariat” from the “elite” sudden force. Tyrol’s (Douglas) role as honest broker and trustworthy blue-collar guy is excellently handled.

The resolution of this unrest is too quick and too neat - though there are a couple of stirring moments along the way - but “Dirty Hands” is astonishing because of the way it brings unfiltered class politics right into focus in an ongoing sf drama. It reflects again the way BSG is able to deal explicitly with things that, in the past, sf dramas danced around using allegory and metaphor and why I still love this show, despite its faults.

I can’t discuss the season finale without giving away spoilers, which would be unfair on the majority who may not have seen it – but I will say that I loved the wily, roguish lawyer Romo Lampkin. SF really doesn’t have enough charming, sarcastic, brilliant Irishmen in it – but if anyone needs another, I do weddings, bar mitzvahs and children’s parties.

So, in some ways the second half of season three hasn’t lived up to the promise of the season opening - but in no way has BSG jumped the shark. Heroes is giving the show serious competition as the best sf on television, but there still isn’t a series on tv - whether genre or not - that can match BSG when it is on form and there is no better or more nuanced political drama on television.