Goggins was offered the role by Sutter because the producer felt that, as Goggins had already appeared in the the long-running cop drama The Shield, and another drama, Justified, both of which were on the US channel FX, which aired Sons of Anarchy, he was too recognisable as those other characters - Shane Vendrell and Boyd Crowder - to bring into a third series. The two shared a joke at the time - Goggins quipped he would have to come on to Sons of Anarchy as a transgender woman to circumvent his familiarity - and a year later Sutter called Goggins back and asked him if he was serious. "I said about what, and he said about being a transgender. And I said, did you write it? And he said, yeah. And he sent the pages and it was like f---ing, yeah." Van Dam was introduced as a transgender prostitute recruited by the gang to blackmail businessman Allen Biacone during Sons of Anarchy's fifth season. The gang later help her retrieve her son, Joey, from the abuse of Venus' mother, Alice, who had taken custody of the boy. She was last seen leaving town with Joey, under the protection of loyal biker Tig Trager (Kim Coates). Threaded through the episodes in which Van Dam has appeared has been the growing suggestion of a romance between Van Dam and Trager. That relationship, and how it unfolds on screen, says the show's creator Kurt Sutter, will be the love story for the show's final season. "Who gives a shit about sexuality any more?" says Goggins candidly when asked about the affection which has grown between the pair. "It's about the quality of the human being that you're with. And I think that if that is the case for Tig and for Venus, but really for Tig, then that just says so much about him.

"It was very important for me and for Kurt for her to come back. We wanted to show the other side of her and that she's a three-dimensional human being and I feel like we accomplished that. People don't get that opportunity that often and it's a real honour to be a part of it." The power of the role, says Goggins, is in the way Venus Van Dam has changed the members of the Sons of Anarchy Motorcycle Club (SAMCRO). "Within the cast of the show, within this cast of fictional characters, that's kind of been the journey, winning them over and if she can win them over well then she can win the audience over, can't she," Goggins says. "And this is arguably the most testosterone driven show on television, really. You know these are tough motherf---ers and for them to embrace her I think says a lot about them. It just speaks volumes about who these people are and how far they've come in their ability to love someone." The transformation for Goggins on set is a process which takes between three-and-a-half and four hours. The show's make-up team, he says, deserve as much credit as he does for the performance. "They own it just as much as I do and Kurt does," Goggins says. "They're extremely, extremely talented." For at least a week prior to filming, Goggins says he is subtly making changes to himself. "I get a facial, I get waxed, I get a manicure and a pedicure, I shave my whole body again and then I shave it again. It's a process. I spent more money to look this way than my wife does."

But the biggest challenge, he says, is not physical, though the physical side of the role takes its toll. "It's not going through the process, although it's a little awkward and uncomfortable throughout the day because it's so hot in Los Angeles this time of year. "The hardest part for me is the extreme insecurity that I've felt, and feel as recent as yesterday, of getting into her and not wanting to do a disservice to this community and trying to do it in a way that is extremely respectful and wanting to live up to that," Goggins says. "And I know Kurt is the same way. I know he has the same fears. We talk about it. And then once we do it then we got it and it's like you just put your best foot forward and know that you're coming from a good place and let the chips fall where they may." And, unusually, Goggins has mixed feelings about the end of Sons of Anarchy and the thought of leaving Venus Van Dam behind. Other characters, he says, such as The Shield's Shane Vendrell, he was happy to see killed off, if only to make closing the door and moving on as an actor an easier process. "But, Venus, I just hope she lives, really. I hope that she lives," he says. "She's touched a different, a real place in me that I just didn't know existed. She's allowed me to see the world through her point of view. It's forever changed me; I get emotional thinking about it. She is here and present and I think the fact that she's transgender is just awesome."

Sons of Anarchy, Showcase, Wednesday 4.30pm (then 9.30pm)