The whose who of Doctor Who

confirming that one of the main four cast members (The Doctor, Amy, Rory & River Song) are marked for death and WILL die in the Series Six opener...

How has this series evolved from last year?

Well we've moved through the funfair a bit – we've done the rollercoaster, now we're on the ghost train. Last year, in a way, was all about saying, don't worry, it's still him, it's still the same show, nothing's really been lost. Losing a leading man like David Tennant is seismic – unless you gain a leading man like Matt Smith. It's been the biggest joy to see him stride in and just claim that TARDIS for his own. But now he's really here, and the part is his, and the bow tie is cool, he's ready to lead us places we didn't know existed. Last year we reassured you – this year, to hell with that, we're going to worry the hell out of you. How well do we really know that man, or what he's capable of? We're putting the "who?" back in the Doctor.

Is there a major story arc to look out for?

Oh, there's a big story being told this year, and major mysteries from the very off. As ever, in this show, the stories all stand alone, and every episode is a perfect jumping-on point for a new viewer. But at the same time the over-arching plot will be a bigger player this year. More than hints and whispers – we're barely 10 minutes into episode one before our heroes face a dilemma that they'll be staring at months from now. And there will be no easy answers.

Will there be new monsters?

They're ... scary. Very scary. And, ohh, I don't want to say more – there's the Silence in episodes one and two, the Siren, in episode three, the Gangers in five and six, all these are more than just freaky costumes and masks; there are SCARY ideas here. And just wait till you meet Idris in episode four.

Is this series scarier than the last one?

See above. Yes, I think so. But it's not JUST scary – it's funny and moving and revelling in its own insanity too.

How have the characters evolved?

The big difference, I suppose, is how long the Doctor is hanging around in the lives of his companions. His normal MO is get them while they're young, and leave them while they're young too. He's careful to put them back where he found them, before he screws up their lives. But here he is, married couple on board – and much as he loves them both, he does wonder if it isn't time he got out of the way; before something really BAD happens.

Did you always plan for Amy and Rory to get married?

Oh, always. Married couple on the TARDIS, that was the plan from the off.

What can you tell us about the cliff-hanger at the end of episode seven?

Normally our cliff-hangers are lives being threatened; with this one, three live are changed FOREVER.

Matt Smith on Series 6:

Matt Smith inhabited the role of the Doctor last year and instantly won a legion of fans with his kooky take on the iconic character. Here he reveals what lies in store for the Doctor and his fellow TARDIS travellers in 2011, and why the Fez is no longer his favourite hat.

"I think The Silence are one of the greatest monsters of recent years and certainly one of the scariest," reveals Matt Smith. "They're also very clever and I love the fact they've been silently working since the dawn of time to make The Doctor come unstuck."

Matt is talking about the new breed of monster which viewers will be introduced to in the opening two episodes of the series. He is remaining tight-lipped about what viewers can expect but he does offer some insights into the story arc for this series. "Steven [Moffat, writer] has a grand plan and some of the seeds he planted in the last series start coming to fruition and affecting the characters in drastic ways," explains Matt. "Every character is faced with the most seismic and high-stakes choices we've seen so far."

Opening the new series is a special two-part story penned by Steven Moffat and set in America, marking the first time in its history that an episode of Doctor Who has been filmed there. The cast spent three days in the desert in Utah but that didn't stop hardcore Doctor Who fans from tracking them down. "It was very strange," laughs Matt. "We were in the middle of the desert and suddenly there was a lady with a campervan and deck chair, holding an iPad up with a moving screen which read 'autograph please!'. I mean how on earth she knew we were in the middle of the desert I have no idea, but it certainly proved her dedication to the show!

"The landscape was incredible," continues Matt, "and I think being in America, filming in that terrain, has definitely added a sense of scale and a filmic quality to this series of Doctor Who. It was an amazing experience and a brilliant laugh. I have to confess that I think the Stetson has been my favourite hat for the Doctor so far, 100 per cent. Viewers may well see more of the Stetson later in the series but I couldn't possibly reveal when..."

Alex Kingston joined Matt, Karen and Arthur in Utah to reprise her role as River Song and Matt admits it was great to have her back. "I'm very fond of Alex and I simply love the part of River Song because it makes the Doctor come unstuck; she's the one person in the world who knows more than him. I think Steven has written some really revelatory stuff about the character and she's extremely important to this series," teases Matt.

"We've also been incredibly lucky to welcome a number of fantastic guest stars including Hugh Bonneville, Suranne Jones and Lily Cole. James Corden also returns later in the series," reveals Matt. "I've admired so many people who have been involved and all of them have brought a touch of quality."

Matt also has high praise for his fellow co stars, Karen Gillan and Arthur Darvill. "I think with Rory, Arthur has perfectly judged the humour and he's got some fantastic storylines with Karen. I do think that Amy and Rory now being married has changed the dynamic in the TARDIS and in many ways it's the Doctor who is perhaps the odd one out," explains Matt. "However, Karen and Arthur are hilarious and together we are always mucking around between takes and telling silly jokes to annoy each other!"

Matt also reveals that his clumsy reputation is still fully justified! "I was chatting away to someone the other day on set and I had my hand on a lamp stand. Little did I know that as I was leaning it was actually turning and suddenly it came crashing down on my head!"

Perhaps it was lucky for the rest of the cast then that Matt wasn't tasked with any sword fighting in episode three which is set on a pirate ship: "It was 4am and we had four huge rain machines making us soaking wet but we all loved it. Karen had to do the sword fighting though," chuckles Matt, "I just had to walk round and act clever in the background!"