When The Mentalist first began, Rigsby was a little immature. Do you feel like he's grown as a character? "Yeah, it's funny; I was talking about this the other day actually. We've obviously all grown with the show - we looked back at the pilot the other day and it's always funny when you look back on something and you think, 'Oh I looked good then, I was really proud of that'. I looked back and I was like, 'Oh my God, I was a child!' so yeah I like to think [that Rigsby has become more mature]. "There's been a lot of things that have happened this season, like all the returning characters coming back. I just finished filming a wonderful episode with William Forsythe, who plays Rigsby's father, and that was a real kind of reckoning moment for me and for the character. "The nature of an ensemble means when you're a supporting character and not the lead character, you get little tidbits here and there, but you're usually there to provide bits of comic relief and little bits of action or something. So when you get the spotlight fully thrown on you in an episode like [season five, episode four] 'Blood Feud', then it really gives you a chance to draw a much bigger picture of who this guy is. "He's transitioned into more serious problems - he's got his job on the line, he's lost the woman that he truly loves and he probably still hasn't given up on her, he's had an unwanted pregnancy with a woman where the relationship hasn't worked out, so there's an awful lot of real-life adult problems that I think would force anyone to grow up really quickly." What was it like working with William Forsythe again? "He's quite an intimidating force in the best possible way. He brings such a level of preparation. He's currently working on another show called The Mob Doctor where he is the head of the mob, so if that's not intimidating enough... you know, 'My Dad is being played by the head of the mob!' "But he's just so full of ideas. We had him for 24 hours to shoot probably 15 scenes and every single one of them was a huge emotional scene. You'll see from the episode, it's a real kind of growing up moment for Rigsby where I think he reflects upon the father that he had and the father he wanted to be. "I love that, I love coming to the challenge. I guess William threw down the gauntlet and it really is a question of... you either bring your best game or you'll just get lost. He's so on all the time and we actually spent almost the entirety of the episode just doing our stuff together, which was lovely. "He's a fantastic actor and I'm really excited for the episode to come out and also I'm excited for Rigsby, I think people will finally get the chance to see that there's more to him than just a quip here and a joke there, with a doughnut or a bagel in his mouth!" Can you give us any hints on where the Red John storyline will head this season? "I think the big question has been, 'When will we see Red John?' and the challenge that Bruno Heller has as the show creator is that it's the raison d'être for the show - if you take away Jane's hunt for Red John, the serial killer who killed his wife and child, you take away his whole reason for being and his whole reason for being in the CBI, so it's a fine balancing act of how much you can tease it out without boring an audience. "Bruno's been very tactical this year and promised we will get within inches of Red John. You know, I'd love to pretend I'm being all kinds of sneaky, but I'll just be dead honest with you and say I really don't know who Red John is! It makes me laugh when you hear actors go, 'I'm gonna have to be top secret about the truth' - I really don't know! I think only Bruno really knows - he decides on where to go with that. "But we've got Emmanuelle Chriqui coming back playing Lorelei this season, which I think was a wonderful injection of life last season. It's really interesting to see the dynamic between her and Jane, and we've got William Forsythe coming back and Summer (Samaire Armstrong), Cho's prostitute girlfriend, is making a return. We've also got Virgil Minnelli (Gregory Itzin) coming back... "It's a season full of old faces and we actually will get to see Jane's daughter, but I can't say in what context. It's a season that really explains where Jane came from and his journey to the CBI and we've been promised from Bruno that we will get literally inches away from Red John this season. This is the big season if you are a Red John fan." Some fans noticed that Jane started going down a darker path last season. Do you think the show can ever get too dark? "I think it's sort of a challenge. I always thought that the show found its groove in the first two seasons by being a mixture. You know, we all love our cop shows like the CSIs and Criminal Minds - all those shows that have thrived for years because it's a classic whodunnit, and everybody loves to solve a whodunnit. "I always thought we kind of managed to stick out from the pack by having that element of human interest. We're not just faceless cops - we're all having relationships we've all got problems, Jane's got his demons, Lisbon's got the issue with authority, Van Pelt's got the trouble with her romantic stuff, and you know Tim's character Cho battled addiction last season, so these are real people and the human interest element is what keeps people going. "We've found that people seem to be responding more to grittiness at the moment. I don't know if that's down to the economy being in a bad place or people just being in a darker place, but they just seemed to have really responded to that and I think it makes the Jane character so much more interesting - under all this lightness, you suddenly see a very dark and possibly slightly mentally unstable place that he comes from. "I think that layers it and I think you'll see this season with every single character, we peel the onion away and see that none of us are stable characters and none of us have come to law enforcement through a very traditional path. Hopefully that'll make it interesting. You know, I'm not saying there's not an element of humour there, but I think Simon wanted to deliberately take Jane down that path to see how much they could push that envelope." How long do you see The Mentalist going on? "I never like to guess. To be honest with you, when we filmed the pilot, I think every part of you as an actor just wants to say, 'Well great, see you next pilot season!' because you daren't wish that anyone will respond to it. This was my sixth series and none of the others had gone, so you just never take it personally. You roll on and you hope that the next one will find an audience. "I know we're aiming for seven [seasons] and that Simon is the producer for this year, so he gets to have a real direct say in the creative [side of things] and I think he's directing a couple [of episodes]. The workload is so squarely on his shoulders with the amount of heavy lifting that the Patrick Jane character does, I think how long the shows continues will rest on; a) If an audience is still reacting to us and b) How much time Simon feels that he can keep the Patrick Jane character interesting, because he works tirelessly to keep that creative and fresh. "I'm a cautious optimist and I would love to see it go the full seven seasons. We are in a world of uncertainties, but we could give the show a nice proper conclusion if we said, 'This is our final season', and we could get the chance to tie everything up. Having said that, would I mind if it ended up lasting for twenty seasons? Not at all." You're a Welsh actor and you've had this big US success. Why do you think there is this trend of non-US actors - Damian Lewis, Andrew Lincoln, yourself - making it big out there? "I always joke that we're cheaper! But seriously there seems to be a real response to British theatrical training and there's a real respect for that. I had the good fortune to go to Oxford and go to RADA, so training is really respected over here. "Also, I remember speaking to a casting director and he said to me, 'It's really funny, America's filled with these very good-looking boyish leading men but we can't get many men's men, so we looked to Australia and the UK because you guys... have that rugged element.' If you look at your Russell Crowes and your Eric Banas - those kind of real leading men - they're all coming from overseas. "I came over to the US in 2004 and it was quite trendy to be British, but now it's quite trendy to be American. It's like, 'Can we get an American to play that American? I'm getting sick of all these Welsh people playing them' [laughs]... but as long as this show continues, I'll be very happy!"