Bluestone 42 is back with a bang

It’s an exciting start that combines the series greatest strengths– gallows humour and idiotic antics (a highlight in tonight’s episode being an inappropriately-timed punching game) interspersed with genuinely impressive (for a sitcom budget) stunts and, of course, plenty of big booms.

“There’s a big explosion in episode 1 – and it’s not even the biggest that we’ve done this series,” affirms Harry Potter star Matthew Lewis, who stars as Corporal Gordon ‘Tower Block’ House in the comedy.

“We have another explosion later on in the series which is the biggest we’ve EVER done. And it is Un-believable. We weren’t even allowed anywhere near it when it went off, we had to watch it from about a mile away. And even then, it vibrated everything around you.”

He adds: ”We’ve really tried to up the stakes in terms of the action and explosions this series. “

Sounds like a real blast – but high-level explosives won’t be the only thing to send shockwaves through the fans this series. Without giving too much away, there are some big changes in the first couple of episodes that will radically alter the status quo of the unit and bring in some slightly more serious themes.

It’s a big risk to have such a shake-up, and frankly some of it doesn’t quite gel. I recently re-watched the second series, and it feels like one or two nascent plotlines from the end of that run have been quietly dropped, with others retrospectively added to help work in these big changes.

So Bird (Katie Lyons) now has a crush on officer Captain Nick (Oliver Chris) despite previous evidence to the contrary, and Nick’s attitude towards his own desire for the attractive female padre has also shifted from where series 2 left it. Still, it's a small complaint and it quickly becomes clear why these changes have been made – I just hold this series to high standards.

Laura Aikman and Matthew Lewis in Bluestone 42

More generally, what can we expect from the new series? Well, from episode 2 onwards there’s a new character in IED expert Ellen Best, played by Waterloo Road’s Laura Aikman and possessing a rather different energy to her laddish new teammates.

“She’s very different from everyone,” says Aikman. “She’s very professional, she’s very by-the-book. And she’s not thrilled with the idea of them being there, having a good time.”

“There’s not an immediate chemistry between her and the group, I think it would be fair to say…they don’t like her.”

And then the series has to deal with the spectre of current events – namely, that we don't actually have troops in Afghanistan any more…

“Obviously, the withdrawal from Afghanistan has happened and that’s something that we touch on in this series,” says Lewis. “The operations are coming to an end, they’re winding down – so in this series it’s a lot to do with looking to the future and how they’ll leave the country.”

Presumably this begins to put the kibosh on any future series of the comedy – but according to the cast, there could be hope.

“There’s so much scope, and the writers have so many ideas for other things the team could do,” says Aikman. “I think technically they wouldn’t be the same team if they went somewhere else, but they might be able to…fudge that.”

In other words, the series could do a Twenty Twelve and spin itself off into another series, with some of the cast moving to a new location as Hugh Bonneville’s Ian Fletcher did to appear in W1A.

So fans need not lose hope yet – but even if this run actually is the last we see of Captain Nick, Tower Block et al, it looks to be a fitting send-off. It has pathos, the usual dark humour, genuinely exciting firefights and an ensemble cast at the very top of its game.

In other words, it’s the bomb.

Bluestone 42 returns to BBC3 tonight (Monday 9th March) at 10.00pm