Let's start by talking about Torchwood...
"That show is the best. I love that show! That show's pissing all the right people off, I love it."
What do you mean by that?
I'm sure in the UK it is accepted for what it is more, but in Mexico and in the United States, there's a good streak of homophobia. A lot of characters are unabashedly bisexual in Torchwood; in fact my character's way beyond bisexual, my character will do anything that has a hole! I used to do lots of plays that could piss people off for the right reason and Torchwood's found a way to do that."
Is that what attracted you to the part?
"No, I wasn't aware of the backlash at the time. I was just attracted to a really good script and a really fun character. I love playing people who are evil, don't care, and have no guilt. A friend told me to watch Doctor Who and I thought 'this is really fabulous actually'. We called Russell [T Davies] and asked him if I could be on Doctor Who and he said 'no', but that I should come over and be part of Torchwood instead."
"Well I can't give too much away, but John has come into league with Grey. When we see him in the holographic image, that is a man who doesn't understand what is truly going on. That's the look of a man who's in way over his head and doesn't even know it yet. Things do change!"
Moving on to Buffy, do you think the Spike movie will ever happen? Is it something you're still keen to do?
"I would love to. My face has held up a little better than I thought it would! One thing I told Joss [Whedon] is that I don't want to do the character when I'm so old that we have to explain that to the audience. I would like to film the character while he's still believably the same age. One of the coolest things about being a vampire is that you are immortal, so I think if we go back to Spike when I can't hold that illiusion, we're going to end it on less than a great note. I went to Joss and gave him an idea for a script that he liked a lot actually."
What's the gist of it?
"Spike tries for the girl, he loses the girl, a monster attacks, he tries to defeat the monster and can't. But he wins a new pair of shoes for himself, because he can't fight any more and his old boots have given up on him. It sounds kind of stupid, but actually when you play the story out it's kind of funny. Joss said 'That's a great idea, I love it, it's cheap' - and it seemed like everything was set to go, but then it evaporated."
Do you think the idea could be revisited?
"I am still interested in it. At this point I would like to do some camera tests to find out if it's possible to photograph me as Spike, but that's not hard to do. With the right lighting, who knows? Maybe I should start drinking carrot juice! The project is not really on the front burner with Joss now. It seems like he made a little attempt and then it just didn't happen. I don't wanna get bitter about it. I was kind of excited that it might happen and I've tried to make it happen.
As you say he's moved on to another project, Dollhouse, which you've been linked to. Any truth in that?
"I'm not familiar with it. What's that?"
(DS explains the concept).
"Wow, that sounds great. He hasn't mentioned it to me, but if he wants me to come and read, I would love to. He's a great boss."
What can we expect at The Rift event and your live gigs next month?
"I think you can expect a very interesting time at The Rift. I'm very happy that we're not only able to get some of the major actors from Torchwood, who are all fabulous people by the way, but also three of the major writers. With the music, people can expect an intimate evening. I just tour with my guitar, and I play these songs that I've written. So, it's a simple evening, there's no bells and whistles."
What else is coming up?
"I just got back from filming Dragonball, so I'm healing from that. I'm going back to do Smallville next week and think I'll be doing Torchwood again before too long. Then resting, and basically working out - Dragonball is all about muscles and I can't be doing the press tour for it without muscles. I gotta pump my pecs. Girls like boobs too, you know."
For more details on The Rift, visit jamesmarsterslive.com. The season finale of Torchwood airs Friday at 9pm on BBC Two.