You've recently had several characters depart the show. Is it always sad to see them leave?
"Yeah, generally it's really sad because we spend a long time getting to know them before they hit the screen and there's a bit of us in all of them. We tend not to make the decision to move a character on unless we really think that it's time. It's never an easy decision to make."
With the new series on the horizon, are you planning to introduce some new faces to the team?
"We are, yes. There'll be some new faces on screen in our opening two-parter over the weekend of September 12 and 13. There'll be some junior doctors to pick up from where Toby and Ruth left off when they were babies, but they'll be very different from them... and there are going to be more of them..." From episode one, there'll be a significant guest character called Alistair – played by Joe McFadden - who'll have quite an impact on Polly the paramedic's life. It gets really, really dark and reaches a rather unfortunate conclusion at around the quarter point of the series. There's also a family that Ruth will get to know quite well and we'll meet them over several weeks, too."
Do you watch shows like Grey's Anatomy? What's your take on UK versus US medical dramas?
"It's very difficult to draw a direct comparison. I watch Grey's Anatomy as a fan and not as inspiration for Casualty material. It has fantastic characterisation, but it's a very different type of show. Although our format's nearly 23 years old, we don't want to start playing with it to make it more like an American show. In the past, perhaps people have tried to do that with Casualty and it's come a bit unstuck. When Casualty works well, it's fantastic and there's a reason why it's lasted so long."
Are there any plans to do another cross-over with Holby City?
"Yes, there are and it's a very exciting one. I can't say too much at the moment, except to say that one of our most important characters will find themselves being treated in Holby City and another of our regulars will go along with them…
"The plan is that in the Casualty episode, which will transmit in February, the leading character concerned will be injured and their life will be saved by another leading regular. They will need to have their injuries treated in Holby City. Mark Catley, who's Casualty's lead writer, will write the Holby City episode, too. We'll then pick up in the next episode of Casualty what happens in the aftermath. It's fantastic to be able to do the crossovers, but the difficulty is purely logistics. We film in Bristol and they film in Elstree. The will is certainly there!"
Is Nick Jordan going to die?
"I couldn't possibly say! Michael French is a truly, truly amazing actor and we're incredibly luck to have him. He's just so clever on screen. When Michael joined us, he joined us for a year's contract, so beyond that point, we'll just have to wait and see..."
Will Jordan and Zoe be getting together?
"Well, Jordan and Zoe will get quite close over the next few weeks, but I'm not sure that either of them are emotionally ready to be together, but it'll cause them to think 'should we?' Zoe's a character who's always been a mistress and she's enjoyed that role, but I think she's heading to a point in her life where she starts to question that. Meanwhile, Nick's suffering from a terminal illness and is probably not in the right place to start any form of a relationship. The story team and I were talking the other day about relationships in the show and we only have one relationship that's enduringly successful - Dixie and Jeff. They've happily bubbled along as a couple and we just love them. With other couples, we need to put a bomb between them it seems - literally, in Casualty's case!"
What's your take on returnees? Is there any chance we could see Clive Mantel back on the show?
"I don't see any problems with it whatsoever if it's a character that the audience want to see. I suppose we could be accused of having done the same thing with Nick Jordan. I know Jordan was a Holby City character, but the eagle-eyed viewers will remember that he was in Casualty first! I'm very proud of his return. If we brought back a lot of characters, it wouldn't be the right thing to do. But if we do it for the right reasons at the right time, I have no objection to it at all."
Do you have anyone in the pipeline that you're thinking of approaching to bring back?
"Not immediately, no. There have been occasions where we've talked fairly non-committally with people who may perhaps make an appearance at a later date, though. We brought back Susan Cookson for an episode and there are surprise guest appearances in the third episode of our new series - one recently departed regular and a semi-regular…"
"Ruth's never allowed romance into her life, but when she starts to get close to Jay, the possibility of happiness with another person suddenly presents itself to her. But the question is, will she allow herself? Or will his laddish ways get in the way? We leave them in a nice place at the end of the series, but it may not last too long... She's so obsessed with her career that she's always tempted to put that first."
Jessica / Adam
"We'll resolve the situation with the children in a few weeks' time because Jessica has never abandoned the struggle to get her kids back. As will the will they/won't they get together - that will finally be answered. As for marriage, wait and see..."
Alice / Curtis
"There are two character that absolutely love each other and I think the audience has really invested their love story across the series. Whether they stay happy really depends on the events towards the end of the series… There's a huge unexpected shock which I think will take people's breath away... It'll rock Alice, Curtis and the rest of the department to their core. I don't think people will be expecting it."
"Charlie's by far our most important character and we have lots planned for him towards the end of the series and particularly into the new series, where we'll see him very much at the centre of the department, leading and being the moral centre of the show."
Do you ever worry that Derek Thompson will leave?
"I very much hope he won't because he's absolutely core to the show's success. He's a fantastic actor and Charlie's a fantastic character. We would never take for granted quite how valuable he is to us. If there ever came a time when Derek said he wanted to leave, it will be completely devastating. It would be awful... I don't know what we'd do!"
What's the situation with Casualty and HD?
"We're not filming in HD yet. We're not quite sure when the switch is going to happen, but we're ready to make the switch when we need to. We had our set revamped two years ago and it's HD-ready."
What's the latest on the set move?
"The move is due to happen around late 2011 and it will be on screen in 2012. On screen, there'll be no difference so the audience shouldn't notice the change."
And also on the cards…
§ We'll be going to some quite dark places with Ruth.
§ Viewers will see what leadership is actually like for Adam.
§ Just as the current series ends with a shock, the new series also begins with a shock…
§ A particularly cold fish character gets a surprise on discovering that they have feelings for someone else…
§ One of our happy characters gets the shock of her life towards the end of this series.
§ Jessica emerges stronger than ever after baby Harry has recovered – but will she be strong enough to take on Sean and win her baby back?
§ And we'll finally discover who the father of baby Harry is.