“Can we just sit here and watch this Spider-Man cartoon?” Mark Gatiss smiles slyly but it’s not clear if he’s completely kidding. We’re sitting on a couch in The Museum of the Moving Image in Queens, New York where a small retro-TV is playing an appropriately retro episode of Spider-Man and His Amazing Friends. “I love cartoons,” Gatiss tells me. “Did you ever see the old Star Trek cartoon? It’s brilliant. It’s basically like season four.”

The guy sitting next to me might look like Mycroft Holmes, but he barely sounds like him at all. This guy is softer, more childlike, more down to talk about whatever, so long as those things are James Bond, Sherlock Holmes, Doctor Who, superheroes, Star Trek… In short, if you meet Mark Gatiss, you want to be best friends with him instantly.

For the uninitiated: Mark Gatiss is the co-creator (with Steven Moffat) of Sherlock. He’s also an actor IN Sherlock as Mycroft Holmes, Sherlock’s snippy, brilliant older brother. He’s written for Doctor Who numerous times, including last season’s “Robots of Sherwood,” as well as the classic Dickens 2005 episode “The Unquiet Dead.” He’s got a recurring role on Game of Thrones as Tycho Nestoris of the Iron Bank, but has roots in the famous British comedy The League of Gentlemen. In short: he’s done some things that are beyond impressive.

Our chat is talking place two hours ahead of The Museum of the Moving Image’s special screening of the Doctor Who episode “Sleep No More,” which is the one Mark wrote for this season. And yes, I can call him Mark, because he told me to. Glancing over at my open-notebook, full of my chicken-scratch questions, he spies the word “Gatiss,” at the top of the page complete with a frantic double underline. “Don’t say ‘Moffat’ or ‘Gatiss,’” he coos. “Say ‘Mark.’”

To say Mark Gatiss is disarming would be an understatement similar to saying Sherlock Holmes is smart. It’s not that Mark is disarming, it’s like you and he have been exchanging dog-eared paperbacks for years and this conversation about the animated Star Trek from the 70s is old hat. After we talk about how great the writing is on that cartoon Trek, I ask him if he’d ever want to write for Star Trek.

“The new series?!!“I love Star Trek, so yeah, I wouldn’t say no. Simon Pegg’s writing the new one [Star Trek Beyond]. So yeah. You never know!”

Is there anything else—any other established universe—Mark Gatiss would like to write for other than Star Trek?

“Nooo…No. I want to do something new. But it’s so hard to get it off the ground. I’ve said this many times, and it’s absolutely true. That there is a reason why people revisit brands that are so familiar; it’s because they’re so familiar! And it’s getting harder and harder to try and convince people to take a punt at something new. So, that is absolutely vital. Otherwise, there’s no blood in it—and I say this knowing that I’m associated with two of the biggest reboots in history—and people will always revisit Sherlock Holmes. And I think that now that Doctor Who has really returned after its absence, Doctor Who is imperishable. It will probably stop again one day and then come back again, because that’s what it does. Like anything. But, I would love to do something that people look back on fondly, because it was a brand new thing. But it’s terribly difficult—A. to think of it! B. To get it off the ground. What is the new thing! Sherlock Holmes himself said there is nothing new under the sun!”

What if Steven Moffat left Doctor Who? Would Mark still write for Doctor Who?

“Of course I’d still write for Doctor Who! If they’d have me! It’s a continuing honor and thrill! I would say that unlike Russell [Davies] saying ‘that’s me, done,’ I think that if Steven were to leave, he’d still come back after a few years and do another one. Because he loves it. I mean, Russell loves it too! But, I think Russell saw it as his take on it and that was it. Which is a very grown-up way of moving on. But I can’t resist the urge.”

When you’re hanging with Mark Gatiss, who wants to be a grown up anyway?

Would Mark want to be the showrunner of Doctor Who if Steven Moffat left?

“The truth is I know how incredibly demanding it is. And one of things that makes it very difficult to see is the sort of casual attacks Steven has had to put up with over the past few years. It’s incredibly hard work and they care so much. It’s a 24 hour job. And when people say ‘why can’t you make more episodes!?’ I mean, the episode we’re watching tonight: I was sent the final effect shot the day before I left for New York. That episode is just complete and it’s on this Saturday. There are so many things to consider. But to answer your question, I know how hugely demanding [showrunning] is, but also how hugely rewarding it would be. It’s a huge, life-changing decision. I’m an actor and a writer. I couldn’t act if I did it. Because I wouldn’t have time. The only thing I could act in would possibly be Doctor Who. WAIT A MINUTE! I’ll DO IT!”

At this, Mark begins giggling like a madman, throwing his head back and repeating “I’ll do it! This will effect my whole life? HA HA HA HA! I’LL DO IT!!”

The comedian, the sketch-comedy writer version of Mark Gatiss has emerged! Fittingly, we switch our conversation to the importance of humor in his writing. How and why is he just so damn funny? Is Doctor Who and Sherlock nothing without humor?

“Humor is fundamental. I couldn’t agree with you more. There’s a fundamental misunderstanding of why we love these shows. Essentially from slightly humorless people who thinks it needs to be po-faced all the time. The man who created the Daleks—Terry Nation—was Tony Hancok’s writer. He was a very, very funny man who could also write great science fiction. That’s what Russell is. That’s what Steven is. What I am. Lots of people. Humor is bound-up in the DNA of [Doctor Who]. ‘Robots of Sherwood,’ for instance, is a straightforward romp. But, you should no more criticize a show for being too funny—what’s wrong with too funny, anyway? You hear that a lot. Someone says ‘it’s too funny.’ WHAT? Too funny? Would your prefer it was moderately funny? I’d go for much too funny any day. That doesn’t mean you’re messing with the format, that you’re spoiling it. And if you look back at the history of the show, that’s what it’s always been at its best. It doesn’t get much grimmer than “Genesis of the Daleks.” But of course there’s humor. Of course there is. It might be pitch black, but it’s there. And sometimes the level is pitched one way and sometimes the other. But to me, it’s absolutely quintessential to Doctor Who, it’s a fun show.”

Though I would have loved to talk to Mark for hours only about Sherlock Holmes and his favorite stories and which movies are his personally, secret preferences, I decide that since we’re already best friends, we’ve had that conversation in some alternate world. Instead, I’m interested in continuity. Sir Arthur Conan Doyle flippantly didn’t care about continuity. Does Mark Gatiss care about continuity?

“Because we live in such an overly-examined age, in which everything is easily consumed and spat-out, everything has taken on a ludicrous level of importance. If Conan Doyle hadn’t had his famously lax attitude toward continuity, we wouldn’t be able to have the fun we have. From speculating on the strange fact that Professor Moriarty and his brother have the same Christian name, that Watson’s war-wound moves about, that Mary calls John “James”! I’m sure people did write to [Doyle] and complain, because there were always fans! But the thing is, it’s fine. My attitude is this: get it right if you can because if you’re perversely getting it wrong, it looks careless. But. Absolutely frankly: if someone came up with an idea for Doctor Who that flatly contradicted something that happened in 1967, fuck it. Of course fuck it! Someone once said to me ‘six months ago is ancient history,’ in terms of television. That’s true, because you’re talking about the general audience and not the fan audience. AND if you flatly contradicted something that happened in 1967, the fans would find a way of explaining it. I remember—in talking about Star Trek—someone telling me that reason William Shatner has so much eye shadow on in “Journey to Babel”—more than ever—is because Star Fleet officers are allowed to wear a certain amount of make-up during formal ceremonies! WHAT?!! I mean you don’t have to explain it! The Master was a snake at one point!”

Looking smooth, and talking smooth are something Mark Gatiss knows how to do, and that’s partially because he’s a big Bond fan. Could secret government mastermind Mycroft exist in the Bond universe?

“He does exist in the Bond universe! We made an explicit reference. In ‘His Last Vow,’ I say ‘As my esteemed colleague is fond of pointing out, what the country needs sometimes is a blunt instrument. Which is M! From the books! And of course I’d love to write a Bond film. It’s the one that’s eluded me. Me and Steven we both wanted to do Bond. I did From Russian With Love on radio!”

As our time comes creeping up on us, and the Spider-Man cartoon winds down, I ask Mark if there’s a world for a gay Bond? What about a straight Sherlock? The last one gets a guttural laugh from him, and we launch into the territory of diversity among established characters and fandoms.

“The point is to me, none of these things should be done because anyone feels pressure to tick a box. A show like Doctor Who has brilliantly celebrated gay people, incidentally, which to me is proper progress. But I think personally, there should absolutely be a female Doctor, a black Doctor, an Asian Doctor, but it’s because someone comes along who is absolutely indisputably the person for the job. With James Bond, it’s a literary antecedent. If you were for reasons of box-ticking made James Bond gay, that’s not James Bond. By all means have a gay spy! I’ve written about one myself! [Mark’s Lucifer Box novels] If you want to do a gay British Spy, adapt my books! That’s my advice. Do a franchise based on my books!”

Will Mark Gatiss fulfill his dreams of creating the next “new” thing that we will all love and obsess over? What is the future for our beloved Doctor Who/Sherlock writer? In addition to a film, more Doctor Who and the three new Sherlocks, that is. What is Mark’s secret project he hasn’t talked about yet?

At this he narrows his eyes, pats my leg and says with a Mycroft twinkle and almost a sneer:

“Can’t talk about it.”

Mark’s Doctor Who episode “Sleep No More” airs this Saturday.

Ryan Britt is a longtime contributor to Tor.com. He’s the author of Luke Skywalker Can’t Read and Other Geeky Truths, out from Plume (Penguin Random House) in two weeks.