Hands up - who's loving Merlin? Now just past the half-way mark, the series has hit its stride with a series of dark, compelling stories and a building mythology that's leading to an almighty climax. Last week I caught up with the show's two young stars, Colin Morgan (Merlin) and Bradley James (Arthur), to see how they're finding the Merlin experience.

How do you think people have taken to the show?

Bradley: "From what I've been witness to, everyone seems to be very positive about it. Nobody hesitates about saying how much they're enjoying it, so I think it's going quite well. But there's still the rest of the series to go, so it could all go wrong!"

Colin: "I think the initial reaction has been great and it's exceeded people's expectations in a way. The episodes we have coming up open it up to a new audience, though. It certainly gets a lot darker and there's definitely a lot there for an older audience."

Have you been watching on Saturday nights?

Colin: "I would watch it on a Saturday, but we get sent the DVDs a few days before it comes out, to see how it has turned out. It takes the pressure off a bit!"

Bradley: "I'm always on a train! I'm never able to get home, but luckily they give us the DVDs."

What's to come in the rest of the series? Nimueh (Michelle Ryan) is back soon, isn't she?

Colin: "We do know that Nimueh plays a huge part in Arthurian legend in general, so Nimueh's business with Camelot and with Merlin certainly isn't finished. She's got a few tricks up her sleeve later on."

Bradley: "I think there's a pressure building on an already-fragile kingdom and yeah, towards the end of the series, with Nimueh's help and one or two other characters, Camelot starts to feel the strain. I think we also look at how Uther (Anthony Head) in particular is going to deal with the situation.

Does Arthur start to twig about Merlin's abilities?

Bradley: "I think the moment Arthur finds out, there will be enough evidence for him to eventually add all the pieces of the puzzle together. Slowly but surely he will, as you say, twig that Merlin's been saving his butt all this time!"

And does Merlin start to realise how Gwen (Angel Coulby) feels about him?

Colin: "I think Merlin has a bit of an odd relationship with girls. In episode four Gwen kissed him - he liked it, but it was a bit awkward for him because I don't think he's had a proper relationship with a girl before. I think it'll take a lot for Merlin to realise what's going on, but there's also a lot to tear them apart coming up."

Finally, have you heard anything about a second series? Would you be keen to do it?

Colin: "We loved doing the first series. It was fantastic and of course, you hope there will be a second series but the reality is, we don't know. It's down to the BBC and if they can afford to do it again, I suppose. I'm not sure about the business side of it but on my side of things, I'd be well up for doing it."

Bradley: "I think things look very positive. We seem to be getting fans and as long as there's that demand to produce the show, I hope it will work out. I personally would love to do it, given a rest first!"

Merlin continues Saturday nights on BBC One.

Merlin - 7.20pm, BBC1

When a Black Knight arrives in Camelot to challenge Arthur and co to single combat, Gaius spots something unusual. The Knight bears the crest of Tristin De Bois, the dead brother of Uther's wife. When Gaius Takes Merlin down to the crypt, they discover that Tristan's body is missing. Has he risen from the dead to slay Arthur?

Colin Morgan - Merlin - 7.20pm, BBC1
Armagh-born Colin, 22 wasn't even out of drama school when he was cast in the page-to-stage adaptation of Vernon God Little at the Young Vic, Colin who says he only ever wanted to be an actor, has also appeared in 2007's The Catherine Tate Show Christmas Special and Doctor Who.