Rebooting a successful series happens frequently in the world of television however no other franchise has rebooted as many times - and with the level of success - as the British series "Doctor Who." As Matt Smith (the 11th actor to play the space-and-time-traveling Doctor) takes the reigns in the latest reboot this weekend on BBC America, how do the creative forces keep the show evolving while also maintaining the elements that make audiences tune in over nearly five decades? Our Jim Halterman talked with Executive Producer and BAFTA-winning writer Steven Moffat about his dreams being realized, the legacy that comes with "Doctor Who" and the advice he gave to Smith when he stepped into the iconic role.

Jim Halterman: You have been a big 'Doctor Who' fan since childhood so the fact that you're now running the show would make one think that dreams do come true, right?

Steven Moffat: Oh, sure. This has become one of the most ridiculous things that has ever happened to me. Growing up, 'Doctor Who' was my absolute favorite program and it's probably what started me thinking I'd like to make up stories like a lot of kids do with 'Doctor Who.' I started to become interested in who wrote things, how television was made but if you had asked me when I was seven or eight what my ambition was I don't think I would have said to be the show runner of 'Doctor Who' because that would be so outlandish. The fact that this has happened is so astonishing I have to remember every morning and think 'Dear God, that's for real! I'm actually doing that!' It's an amazing twist in the tale!

JH: Now that you're at the helm, do you have to work to keep the old memories and versions of 'Doctor Who' out of your mind so you can move forward with it?

SM: I don't find that a problem to deal with at all, to be honest. I've held onto how I felt about it as a child now that I'm an adult and I didn't let it get in a way. You're not making a new show for nostalgia sake so people like you can come on board and not feel like you're missing the part for the last 45 years or whatever it is.

JH: What's the one through-line that has been a part of all the 'Doctor Who' carnations since the beginning?

SM: I don't know if there is one. It's a show whose precinct is everywhere and every turn that ever has been and ever will be. 'Doctor Who' is a madly varied program. One week we're doing a comedy set in historical times. Next week we're doing a dark thriller set in modern day times and next week we're doing one about a man sent into the future. The one thing that I suppose is this wonderful central character who has a tremendous sense of adventure and can get into trouble as quickly as possible and you just want to be his friend or be his mate and go off and explore the universe. I think every child and every adult has that fantasy that the Doctor would land their garden and the Doctor would take them away.

JH: How do you strike the balance between the humor, adventure and sci-fi/fantasy elements so one doesn't overtake the others?

SM: I don't know. The hell with balance. What would happen if you pushed every button at once? That's the kind of show it is. It's got big ambitions so we tend to be funny and scary and mad and silly and moving all at the same time. That's Doctor Who. That's the scale and the energy of it.

JH: Matt Smith seems to effortlessly step into the role of this latest Doctor. Can you talk about casting him?

SM: In the traditional way, he turned up at an audition and was just staggering. He was brilliant. As you can realize, it's one of the biggest parts you can play in British television as well as any part of the world. There was a long list of incredible people that we saw but on the very first day of the auditions Matt just knocked it out of the park. He had everything that you sort of need. He's handsome. He's angular in a strange, exaggerated way. He's got the head of a cartoon and he's got the body language of an aging professor in the body of a hot young bloke. He's a massive, fascinating contradiction. He's halfway between Stan Laurel and Indiana Jones. He's just everything the Doctor should be. The Doctor should be an impossible mass of contradictions.

JH: After so many actors have played the Doctor - David Tennant played him up until January of this year - how did you advise Matt to take on the role?

SM: I'm a big believer in that you should not have to explain anything about a part. It's in the script and if it's not in the script it ought to be. What I said to Matt was 'You'll make this your star vehicle. You'll make it your own. Make it your star part.' Every Doctor has been a big hit and there's been quite a few. So, just grab this opportunity and say 'I can be a star in this part.' That's what's happening in England at the moment even after two episodes. He's just taking over that role and that show so magnificently.

JH: Besides running the show, have you had fun bringing in some guest stars that maybe you've always wanted to work with?

SM: We've brought in some fantastic guest stars but we're quite strict - we don't ever cast anyone for the sake of it. Whenever I write the script, I don't think about who is going to be in it. I try to write the best script and then cast it properly.

JH: How would you prep a viewer who is new to 'Doctor Who' to dive into this reboot?

SM: It's the adventures of a man who can move anywhere in time and space. That's a pretty cool format, don't you think? Every other TV format can hang its head in shame! It's just a rollicking adventure series that entertains by any and every means possible.

"Doctor Who" returns this Saturday on BBC America at 9:00/8:00c.