"Doctor Strange" (out on Blu-ray on February 28) sees the gifted neurosurgeon Doctor Stephen Strange (played, winningly, by Benedict Cumberbatch) have his hands crushed in an auto accident, leading him to seek more alternative therapy on the other side of the world. That's where he gets involved in cosmic impossibilities, battling giant monsters, dabbling in time travel, and generally teeing himself up to be the Sorcerer Supreme of the Marvel Cinematic Universe. It's so, so good.

Earlier today, I sat down with director Scott Derrickson, who spoke to me about Dan Harmon's contributions to the final movie, why Cumberbatch also played the film's otherworldly baddie, and whether or not the mystical stronghold changed its password after one of its members went bad.

It goes without saying that there is a very heavy SPOILER WARNING issued for the following, but since everyone and their magical cat already saw this movie, I'm less concerned.

Moviefone: Just wanted to start off with a serious question: Did they have to change the Wi-Fi password at Kamar-Taj after Mordo left and went bad?

Scott Derrickson: No, I think they would keep that Wi-Fi password.

So, if Mordo was in the neighborhood, he's got his laptop, no problem.

Well, as you know, accessing Wi-Fi doesn't mean accessing any systems within Kamar-Taj.

Oh, that's true. So, this is such a unique take on the Marvel Universe. Was there ever any push-and-pull in terms of just how far you could push things?

Yeah, it was. The common criticism I had seen was, "Every Marvel movie ends in a big fight, where there's a portal opening to some other dimension and they destroy a city to close the portal." So I thought, "OK, what if we have the un-destruction of a city and, instead of closing the portal, we go into it and go to the other side." So that was the idea. Before we'd even written a script I said, "I want this final battle to be people fighting forward in time while the world is un-destroyed in reverse time around them." It was just a concept and an impossible one, one that had never been done. But I just said, "Well, let's write it and figure out how to do it. And that's what we did."

Jon Spaihts was there and Stephen Broussard was there, and we started the batting the idea round. We were about to leave. We'd been working for hours and right as we were about to leave, I threw that idea out there -- while we were standing there -- and started throwing it around and by the end of that session, we had the concept.

Jon went away and wrote it. And out of all the things from the first draft of the screenplay that Jon wrote, that's the section of the script that remained untouched. It came in so good that we said, "This is the end of the movie. We're keeping it."

Another aspect of that final sequence is Cumberbatch playing Dormammu. How did that come about?

It was actually Benedict's idea to start with. He was asking who was going to do it, and I didn't know because we hadn't cast anybody yet. I think he was just asking in passing. Then he came back to me and said, "What do you think about me doing it?" And I said, "Well, why would you want to do it?" He said, "Well, I think I'd do a good job," which was a great answer. So I told him I'd think about it and went away and thought about it and I thought: "Nobody could understand that character better than Benedict because he knows the movie inside and out." And the fact that he was game to do it and willing to do it was great.

The last screening I did for the film was at USC, my alma mater. And Kevin Feige is also a USC graduate. So we agreed to do a screening and it was on the Friday night of its release, so the reviews had already come in. It was over 90 percent on Rotten Tomatoes and the box office projections were in the . So I knew it was a huge success.

I was standing outside the theater at USC, waiting alone, and here comes Kevin walking up, and he's so approachable and down-to-earth. He's wearing his ball cap and his sweatshirt and his tennis shoes and drinking a Starbucks. He said, "Well, how do you feel?" I said, "I feel relieved." He kind of smiled. I said, "Kevin, someday somebody's going to make a bad Marvel movie. But it ain't gonna be me." He laughed really hard at that.

What was your main takeaway from the Marvel process? A lot of filmmakers talk about what it's like going in there and trusting the machine.

It's not a machine at all. I think the biggest takeaway is that Marvel movies and the quality of Marvel movies are the result of a handful of creative people who are producers, but they're artists and film-lovers first. They approach the creative process without any ego at all. They're not egotistical, they don't need to be right, they don't need to have things done their way -- and you go in with all of your talent and all of your skillset as a director and all of your vision, they hire you for that vision. They want you to make your movie. They are there to help you and help find the best possible ideas. So, if your ego is checked at the door, everybody finds the best idea together. Everybody wants somebody to have the best idea, all the time. There's very little arguing or conflict. It's mostly just hearing ideas and shooting ideas back. The best idea always wins.

No! I'm excited to see what the other filmmakers do with him! I get asked this question a lot and it would probably make me a little uneasy, but I love these filmmakers so much. It's like, "What's Taika going to do with Doctor Strange? I can't wait to see that!" He's an extraordinary filmmaker.

I only know the story of "Infinity War" because I ran into (co-director) Joe Russo outside the bathroom at Marvel, and we got to talking, and he pitched me the movie while we were standing there. So I know the story, but I don't know how Strange fits into it and I don't want to know. I want to go to those movies and be surprised by where the character shows up.

It was reported that Dan Harmon was brought in. And just as a fan of his I was wondering what he brought to the movie.

Well, Dan is a proper genius. He really is. Joel McHale is my best friend, and my family and his family have a BBQ together every weekend, that's no exaggeration. And my kids have seen every episode of "Community," which means that I have seen every episode of "Community" multiple times. The more I watch that show, the more I think he's a certifiable genius. He really is.

I know nothing has been announced, but is this a character you'd like to return somewhere in the Marvel Universe?

I hope so. I love the character so much, and I also love the incredible possibilities that the movie opens up for future stories. So all the timing would have to line up and all of that kind of stuff. But I hope so.

"Doctor Strange" hits Digital HD and Disney Movies Anywhere on February 14 and Blu-ray on February 28.