'Loki' Creators on Exploring Time Travel and What Makes a Villain a Villain (Exclusive)

Writer Michael Waldron and director Kate Herron talk about the God of Mischief's Disney+ series.

To mix and match a few superhero mottos: With glorious purpose comes great responsibility. So, when Marvel Studios decided to give Tom Hiddleston's Loki -- dead in the MCU proper but still very much alive in an alternate timeline created during Avengers: Endgame -- his own streaming series, head writer Michael Waldron and director Kate Herron realized that getting to play with one of the most coveted toys in Marvel's sandbox also meant burdensome expectations.

"The key thing for me and the writing team and Marvel was just, there has to be a good reason to go back in with this character," Herron explained to ET's Ash Crossan. "And definitely take him to new places but paying respect to the character that's come before, because he is so beloved."

Titled simply Loki, the series reveals what happens to the God of Mischief after he steals the Tesseract during Endgame's Time Heist. What happens is he lands in the bureaucratic hell of the Time Variance Authority -- middle-managers of the "sacred timeline" -- and is recruited by Agent Mobius M. Mobius (Owen Wilson) for a new mission involving time travel, variants and-- Well, saying much more would spoil the mischief to come.

Ahead of Loki's premiere, its creators spoke to ET about exploring the gray area between superhero and supervillain, Hiddleston's encyclopedic knowledge of his MCU alter ego and the name that's still on everybody's lips: Mephisto.

ET: WandaVision was such a wonderful exploration of grief. The Falcon and the Winter Solider was about identity. What would you say is the central theme of Loki?

Michael Waldron: It's about finding out who you are, in a way, and also about identity. Falcon and the Winter Solider, you stole mine there. It's about what makes a villain a villain? What makes a hero a hero? And can you be both? In movies -- big blockbuster superhero movies -- you sort of have to play in the good and evil thing. TV, there's more time, and you get to play in the shades of gray, and I think that's where Loki's always lived. So, it's about Loki further examining who he is as a character and why he is the way he is.

Kate Herron: For me, a really central theme is, Is anyone truly good or bad? And are we always going to be defined by our past actions? Or can we move past those. And I think Loki, he's the perfect example of that gray area in between, and he flips between good and bad constantly. That is definitely a central question not just with Loki, but across the entire show.

Loki is obviously a fan favorite, but we've always seen him tethered to Thor or to Asgard. How different is he now that we're seeing him on his own? What would you say is the biggest difference from what we've seen with him before?

KH: Obviously, he's had one of the best arcs across the last 10 years of the MCU, but we don't have that guy that we saw in Infinity War or in Endgame, who's obviously Avengers Loki. The exciting thing for me as a storyteller is that he's in a very different headspace to the Loki we've seen over the last 10 years, and we're putting the God of Mischief into this bureaucratic organization and how is he going to cope within that place? I think we're taking him to a very new corner of the MCU and there's a lot of fun to be had with that.

MW: He's gotta fend for himself. He doesn't have anybody else he can look to to sort of take advantage of, to get out of jams and everything. He doesn't have anybody he can blame things on. The messes he's making now are his own. And that's not to say that he was ever passing the buck. It's just, this is a guy who's always been really connected to Thor and really survived by being close to power and then seeking to overthrow that power. Now, he's on his own at the bottom of a ladder, at the bottom of the food chain, so it's just a totally new dynamic for him to be playing with.

Marvel Studios
'Loki' director Kate Herron with Tom Hiddleston and Owen Wilson. (Marvel Studios)

Tom knows this character inside and out, and he's also an executive producer on this. How closely did you work together, and were there moments where Tom would be like, "Loki would actually say this"? Can you think of a moment on set where he took what was written and made it even more Loki?

MW: Tom and I worked really closely and became great pals, that was one of the great pleasures of the show. He came to the writers' room and sat with all of us and spent a full day answering questions, talking about the character, talking about the motivations behind choices he made in the very first Thor movie, when he was shaping the character with Kenneth Branagh 10 years ago. And then after the writers' room wrapped, when I was rewriting all the episodes, Tom and I, we had a couple of marathon breakfasts around L.A. when he was in town, just talking about the character. You know, "How would Loki say certain things?" Tom's English. I'm from Georgia. It was like, "Let's make sure Loki doesn't sound like he is from the South." So, we were refining it together, but that was an amazing collaboration.

KH: I did a lot of table reads with the cast before we filmed and a really key thing for us was talking about the memories that Loki sees in the Time Theater. Tom was definitely contributing to that discussion. And Tom is an encyclopedia of Loki knowledge, so it was amazing to have his input into that. In terms of something amazing on set that I weirdly just remember, there's a moment in episode two where, basically, it's a scene with him and Mobius and I had to film it in one take because we were up against the clock. And I remember that we were trying to block it and I was like, "It's just not quite working." And Tom was like, "Wait. Watch this. It's going to be great." And I remember him and Owen just went off into the elevator and then came out and it was honestly like watching two ice dancers dance around each other. It was amazing. People can see that in episode two, but they just did that and I was like, "This is incredible." So, it's not so much a Loki thing, but just an amazing Tom thing.

Endgame did time travel with the Time Heist, and of course, it has been extensively debated and dissected by the fandom. Wrapping your head around the time travel concepts, is that something that would have you spring up at night, like, "Oh my gosh, that doesn't make sense. I gotta go rewrite that part"?

MW: I would not even sleep at night. There was nothing to spring up from! I was so stressed by the time travel. That was certainly the biggest challenge of the show. Endgame was a movie about time travel but ultimately when that movie is over, you get to walk out and it made sense and all worked. But this is a TV show, and our time travel logic is going to have to sustain week by week, and that means a week of scrutiny by the fans between every episode. As they should! It's exactly what I would do if I was watching this. So, that meant that in the writers' room, we were drawing a lot of lines with other squiggly lines coming off of them on the whiteboard, because we had to essentially create a foundational knowledge of time travel in the writers' room that the TVA was going to work off of and invent the rules of time travel so they could then be broken. That was a fun but challenging part of the job.

At some point, you need to release all of the squiggles and maps you were making, because I'm sure it was amazing.

MW: What's funny is they all probably look the same, except to all of our writers, all of whom could start arguments with one another even a year and a half on about, "No, that's right! That's right!" It was fun.

I don't know how online you are, but there was a big Mephisto conversation around WandaVision and we were all going nuts. There is a moment here [previewed in the trailer] with a stained glass window showing a devil and I could have sworn we were talking about Mephisto for a second. I have to know if that was intentional or not, or am I still stuck in what happened with WandaVision?

KH: It's honestly just a super weird coincidence. Like, it's genuinely a reference to Loki -- the horns, he was cast out of heaven, that's what it's a reference to. Because we filmed that a long time before-- I think WandaVision must have been in post when we filmed that. I did see all the stuff about that online and I was like, "Oh, this is going to be interesting." [Laughs] But no, it's more relevant to the themes of our show and it's not a nod to that character.

MW: Mephisto, I was just reading about that character. It's pretty interesting. It would be interesting if he ever showed up in the MCU.

Loki premieres on Disney+ on Wednesday, June 9.