On Monday of this week, we introduced a sweepstakes package that Ars would be giving away to commemorate the 50th anniversary of the BBC series Dr. Who. To celebrate, we're giving away prizes to two lucky winners. This first prize is "The TARDIS prize package" which consists of three official books: a copy of A Plague of the Cybermen, by Justin Richards with a signed bookplate, a copy of The Dalek Generation by Nicholas Briggs, and·a copy of The Shroud of Sorrow by Tommy Donbavand. The second is the "The Time Lord package" which is a Blu-ray DVD Giftpack of Doctor Who, featuring Matt Smith (Seasons 5, 6, and 7).

Haven't entered yet? Don't worry. You have one day left: the contest ends on Sunday, April 21 at 9pm CT. Simply go to our sweepstakes post here and share your love for Doctor Who in the comments. You can tell us who your favorite Doctor is, what episodes make your best-of list, or how you got hooked on Doctor Who in the first place. Winners will be selected through a random drawing and contacted by e-mail. (Sadly, you must be at least 18 years old and a resident of the 50 United States and District of Columbia to participate this time around.)

If you've already entered, read on for an interview with author Justin Richards, who wrote one of the forthcoming books we're giving away, as well as a quick (and necessarily incomplete) refresher on the Doctors Who, with a poll at the bottom so you can tell us who you think is the best.

The man behind the curtain

The Dr. Who series has inspired feature films, spin-off plays, trinkets (see: editor Megan Geuss' "You will all be exterminated" novelty coffee mug), fan fiction, and perhaps most obviously, books. British sci-fi and fantasy author Justin Richards has written extensively for BBC books, and his most recent release, Plague of the Cybermen is just the latest chapter in the Dr. Who canon. Besides being a prolific author, Richards is also the creative consultant for BBC Books' range of Doctor Who fiction.

Ars asked Richards a few questions about the universe.

Ars: In celebration of the 50th anniversary, can you share with our readers a little-known fact about the books and novelizations that they may not know?

Richards: For several years now Doctor Who has held the world record for the largest number of books centered round the same fictional character. The first Doctor Who-related publication was The Dalek Book; in June 1964—an "annual" with text stories, comic strips, features, and artwork. I don't know the initial print run, but a follow-up book, The Dalek World, published the following year had an initial print run of 300,000. The first Doctor Who novel was Doctor Who in an Exciting Adventure with the Daleks which is a retelling of the first Dalek story, written by David Whitaker from Terry Nation's scripts. It's been reissued recently by BBC Books with the less cumbersome title Doctor Who and the Daleks. Unusually it's told in the first person by the character of companion Ian Chesterton.

Ars: How do you decide what characteristics each doctor retains and and what changes with each successive doctor?

Richards: A lot of that is down to the actor, of course. For the books we very much have to reflect how the character is defined and played in the TV series. That can be quite tricky with a new Doctor as the timing of TV production compared with publication doesn't work in our favour! So when David Tennant took over and became the Tenth Doctor, the three authors working on the first set of books—including me—only got to see rough edits of his first episodes a couple of weeks before we had to send the books to print. You can only glean so much from the scripts, and so we needed to do some frantic rewriting and amending to get the character of the Doctor spot on for those books!

Ars: Can you explain the ways in which the novelizations of Dr. Who interlock with the TV series in interesting ways?

Richards: Basically, the TV series has a trump card—in any overlap, TV wins! So when we wanted to include Winston Churchill in a novel, the TV production people said, "Actually, please don't because he's the sort of historical character we might want to use in the future and we'd rather the books didn't get there first and set things up we might not [be able to] fit in." In fact it was a few years later—and a different production team—that eventually had Churchill appear. We didn't tell them he'd been in the books years ago already, albeit as a young man… But generally there isn't too much of a problem. We check out every outline before we start to make sure that we're not telling a similar story to something they're planning for TV so we can adapt before we get too far in. Obviously we reference the TV series and continuity where we can and where appropriate. We make sure the stories told in the novels fit very much into the overall continuity.

And it works the other way too sometimes. The Slitheen's rivals the Blathareen first appeared in the novel The Monsters Inside, as did the planet Justicia which Rose talks about having been to in one of the Ninth Doctor episodes… So we're all living in the same narrative universe.

Ars: Doctor Who has always taken tiny cues from what's going on in politics and science in the real world. How has it changed and do you see that as a good thing or as something that can't be helped when writing science fiction?

Richards: I think it's both: it's a good thing because it reflects the world we live in and maybe makes people think about that critically. And because no writer—for the TV series or the novels—works in a vacuum, it's inevitable. We're all influenced by what's going on around us, and it comes out—to a greater or lesser extent—in what we write. Has that changed? Only in so much as scheduling has changed. Way back, we used to have a Who novel written and edited maybe eight to ten months before publication, so topical subjects might have become stale news. Now, because we have to fit to TV schedules our own [schedules] are much more curtailed. So the three novels we have out this month (April) were still being worked on right through January!

Ars: Who's (pun intended) your favorite literary Doctor, and who's your favorite TV doctor? Why?

Richards: That's a such a tricky question—and one that everyone asks! But you're comparing like with like. [This question] isn't like 'Who's your favourite James Bond' where you can select from actors all playing basically the same role. The Doctor becomes a different character. Yes, his underlying morality and goals remain the same, but not the way he goes about things, or speaks, or behaves to other people… That said, my favourite Doctor from the classic series is the one I sort of grew up with—which is very often the case—and that's the Second Doctor played by Patrick Troughton. My favourite to write for? Again, they're so very different it's hard to say—each offers their own challenges and joys. I did very much like the Tenth Doctor—he works very well on the page as he talks so much, and dialogue is easier to reproduce than detailed mannerisms and physical traits. Easier for the writer to convey and for the reader to absorb. But there isn't a Doctor I don't enjoy writing for, there isn't a Doctor I don't love watching!