What can you tell us about the new series of Foyles War?
"It's very exciting - it's only three parts this year, so they're all like mini movies. It's all about the period after the war, so it's the tough time in England. Foyle's obviously not working for the police force any more - he's an advisor and he's finding it hard to take his retirement seriously."
Your character is brought in for a love story, isn't he?
"Yes. My character - Adam Wainwright - bumps into Sam in London and through the depressing time in England, they find a love between them while battling through different scenarios. They become very close and Foyle sort of hands Sam over - it's like the father approving of the new boyfriend!"
Were you nervous about joining a long-running series?
"It's something I'd watched and I was a big fan of Honeysuckle [Weeks] and Michael [Kitchen], so it's always a bit strange coming into something so established and playing a new big character. With a devout fan base, the pressure is on! But they were more than welcoming and the character is so lovely, so it was too good an opportunity to turn down, really."
Where does Adam end up by the final episode?
"He has inherited this house off his aunt, who is the only close one to him in his family. He's realised that the brilliant brain he has for maths is completely useless at that time, so he inherits this guest house and starts to run it as best he can. In the meantime he becomes a campaigner for everything British and everything right."
The series was brought back due to demand from fans. Does that mean it's likely we'll get another series next year?
"It's interesting because obviously it was brought back because of the fanbase and it's called Foyle's War but now it's set after the war! I don't know what the next step for Foyle could be. There's always crimes to be solved, so there is opportunity to do another one, but we'll see how well this seres is received. I had so much fun on this that I'd love to come back."
You're also coming back for the final series of The Tudors...
"Yeah, I think it's getting a mid-June release date in this country. Edward Seymour has stepped up to a whole different level in the final season, so it'll be exciting to see how that's received. It's great, and it's such a big piece of work. The only problem is, the words are almost poetic - they're impossible to learn sometimes! There are words and phrases that you've never come across before so if you're trying to ad lib to get yourself out of forgetting a line, there's no hope for you on The Tudors! That show has taught me to learn my lines perfectly."
What's it been like working alongside Jonathan Rhys Meyers?
"Jonny's great - he's got such a great energy on set and is someone who is always word perfect. You can often work with people who are quite safe, but Jonny always likes to push the boundaries and do something different in a scene, which will sometimes work and sometimes not!"
Joss Stone got some bad press for her acting abilities when she first popped up on the show...
"She was so lovely to work with. I thought she did a great job! I only had a couple of scenes with her, but in those I thought she was great. It's funny how well-received she was in America compared to here. I guess they haven't heard her German accent or whatever! But the accents are all over the place - there's a European sound to everybody."
Obviously the show follows history, but how does the final episode of the series end?
"It's hard to say without giving it away. But it depends what side of the camp you're on as to whether you'll be happy or not!"
Foyle's War returns Sunday at 8pm on ITV1.