As far as heroes come, they don't come any more straight forward than Stargate: Atlantis' Colonel John Sheppard, as played by Joe Flanigan. Cool in a crisis, dry of wit, resourceful, yet ultimately, just an ordinary guy, he's a charming chap who's never going to leave a team member behind, and will never give up, no matter the odds.

The one thing that strikes you as odd when you meet the actor who plays Sheppard is that either he's the perfect actor, or he's perfectly cast, because he seems to have the easy, heroic charm of a man who's looked death in the face, made a sarcastic and rather wry quip, and then gone on to save the world and himself anyway. It's quite an unnerving quality, but it's something that doesn't take long to get used to, and before long you're yapping away like chums discussing a hard day at the office -- or in his case, a hard day fighting off The Wraith, Replicators and all manner of intergalactic foe that threaten Atlantis on a daily basis.

RT chatted with him about Season 4 (which comes out this week on DVD) and touches on Season 5.

Season 4 has some pretty interesting episodes, starting off with the tremendous special effects display in episode one, but you had a personal journey in the episode, Outcast.

Outcast came from an original idea that I had that Ronon and Sheppard had to go back to Earth because Replicators(self-building super intelligent, super strong robots who take human form  and want to kill all humans) had gotten on world and were being insidious, but it was basically us running around on Earth in familiar areas and blowing things up. They liked that idea and wove some backstory in it about my father passing away. It really took it to the next level, and we got to see a lot more about Sheppard and who he is.

What's it like having a new boss in Season 5?

Our hot new female lead, Robert Picardo! I guess we were expecting an adversarial relationship, but it didn't work that way. It was generally constructive, however. The writers like to make sure that people don't get along. We found a moderate form of that, where he likes to be the peacock, where he likes to be in charge, stick to protocol, but when you close the doors, there's a sense of humility, and he doesn't know quite what he's doing, and he looks for advice. We've had a few scenes together -  it's not all that different from the relationship that me and Amanda (Amanda Tapping, who played Samantha Carter, head of Stargate:Atlantis in Season 4) had -- Amanda's perfect, on screen and off screen.

To be honest with you, it's quite smart. If he came in too bombastic, it wouldn't work. It would be fun to have that bureaucratic antagonist, messing with us, we need a loathsome bureaucratic personality.

What do you think separates Stargate: Atlantis later seasons from other Sci Fi shows?

I think we're going to emphasise a lot of action. I've been proposing a huge action episode with no dialogue, where Sheppard will just be fighting for his life, which will be a nice counterbalance with the high concept. I know that our show does air on a few 'Action' networks, and I was astounded by how little action and action shows are on TV.

And I like action/adventure, and I've also learned to really like Sci Fi. I'm all about action, and I think it's also a great way to reach out to a broader audience.

I'm a bit simple when it comes to watching TV, if someone's there trying to talk about something, I'm more than likely going to change the channel, but if you're watching someone getting the crap beat out of them, fighting for their life... oh well! Look at that! Turn that up!

Will we see more sparring sequences from you?

Well, when it comes to fight scenes, my solutions tend to be more Harrison Ford in Raiders of the Lost Ark, pistol finishes it off sword fight sort of thing. I'm kind of sloppy. When I started, Bam Bam,  (James Bamford) our stunt co-ordinator, talked to me about what kind of fighting I'd be doing.  

At the beginning of the show, he thought I was going to be this martial arts expert, where I saw the character as more of this regular guy, flying by the seat of his pants, hoping to somehow get through it, lucky to pull this thing off. It's fun to have those martial artists on the show, but chances are Sheppard's more likely to have a beer in his time off than sparring.

You talked about the kind of TV shows that you like. Can you be specific?

I don't watch a lot of TV -- I do like to buy DVDs of TV and watch that. It's the best way to watch TV. You can see it all the way through, no commercials. I like Entourage, I really like Deadwood -- I would love to do a western. I don't watch Reality TV -- it frightens me to the depths of my soul.

How do you explain the success of Stargate: Atlantis?

I think the show works because of the chemistry of the characters, and because it doesn't take itself too seriously. You can maybe get away with a $150 million movie, you can be serious. If you're doing a 44 minute Sci Fi show for $3 million you can't come off being pretentious and too serious.

Even all the dark characters, the edgy shows that  some very well-known show runner shave put up  - the characters are just not likeable, and that's why they haven't worked as well.

I think that we're lucky - our characters are likeable, and we enjoy ourselves, and it shows . And to know when the adventure is urgent and when it is funny is key. Comedy and humour are probably the saving grace for us.

Where does the inner strength of Sheppard come from?

A lot of it is survival. He wants to live! A lot of those situations he's in, he's about to die! That never give up thing, that whole loyalty thing is something that always plays well with audiences, it's a quality I admire.

You got to do quite a lot of cool makeup effects in Season 4 - have you had any episodes with prosthetics this year?

Not this year. But that kind of thing, I had no problems with it. I mean Rachel's doing it tough this year as she's becoming a Wraith Queen, and I was talking to her about it and she was saying that she was a bit upset about it -- "I'm going to look like a monster!"  I just thought it was hilarious. Of course the real problem when she's breast feeding in makeup - that's going to leave a whole lot of psychological detritus!

Stargate Atlantis. Season 4, now available on DVD.