"What if?" It's a nagging and often alluring question — and it's the center of everything on Amazon's new drama series The Man in the High Castle.

Based on the Philip K. Dick novel of the same name, the series is set in 1962 and imagines a world in which the Axis powers of Germany and Japan won World War II instead of the Allies. After Hitler dropped a nuclear bomb on Washington, D.C., America is divided into two occupied states: the German Reich controls the Eastern and Central U.S. while Imperial Japan rules over the West Coast and Pacific states. (There is also a third, seemingly lawless region known as the "neutral zone" along the Rocky Mountains.)

The concept was one that thrilled executive producer Frank Spotnitz (The X-Files) the first time he read the novel in college. "It really struck me when I read it because it was a story where the good guys didn't win," Spotnitz tells TVGuide.com. "It was about living in defeat and that really haunted me. So, when Spotnitz got the call to adapt the novel three years ago — after five years of other creatives toiling to bring the story to TV — he jumped at the chance. But after revisiting the source material, he discovered he'd taken on quite a challenge. "I realized 'Wow - there's a reason why it hasn't been made in all of those years even though it's considered Philip K. Dick's best work. It really isn't a television narrative," Spotnitz says. "It's more about characters living in this world and not a story that would drive a television series."

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Indeed, the early chapters of the series often struggle with plotting and pacing as the show sets up its characters and establishes its global stakes. Our primary point of view character is Juliana Crain (Alexa Davalos) a young woman in San Francisco who discovers a newsreel film that shows footage suggesting the Allied Powers didwin the war — presumably made either by or for the mysterious Man in the High Castle. Is it from an alternate universe? Is it some sort of conspiracy? Juliana sets off to the neutral zone to find out, leaving her boyfriend Frank (Rupert Evans), a jewelry maker who's hiding his Jewish heritage, behind to suffer the brutal consequences of her actions.

In the neutral zone, Juliana meets Joe Blake (Luke Kleintank), a young man from New York who positions himself as a fellow recruit to the resistance movement but is actually a Nazi double agent working under the command of SS Obergruppenführer John Smith (Rufus Sewell). "You're never sure who he is and whether he's good or bad and whether he can be trusted or not," Spotnitz says of Joe. "He does seem to be attracted to her — something about her humanity is appealing to his better nature. But you can never be sure with that character, which makes you uneasy. He does seem to have genuine feelings for her but you don't know what the limits of those feelings might be."

Joe isn't the only one who finds Juliana's humanity alluring. "The reason Juliana is the heroine of this story, to me, is that she has an innate humanity, even more than she realizes she has," Spotnitz says. "The themes [of the book] are: What is real, what is reality itself - which is a hard thing to even grasp, let alone dramatize. The second one is what is human and how do you stay human if you're living in an inhuman world? [Juliana's] somebody who's got a largeness of spirit and not a lot of people have that quality as she does. To me, she's hope. She's light in this series. That's why, as dark as this world is, I don't think the show feels depressing, because it's about hope. And life."

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But there is plenty of darkness. Once Juliana escapes, Frank is arrested and tortured at the behest of Inspector Kido (Joel de la Fuente), the leader of Japan's military police. Like Obergruppenführer Smith, Kido is a character Spotnitz added to serve as antagonists that were absent from Dick's novels. And although Spotnitz felt it was necessary to show the ruthlessness of these two regimes, he also made it a point to rationalize the villains' points of view.

"It's one of the things that was most important to me about doing the show," he says. "We too often think the Nazis are just the bad guys in Hollywood. Of course, Hitler was evil and he was a madman and a psychopath, but not all of the men who fought in the German army were evil. A lot of people who loved their wives, were good fathers, were honest and trustworthy in other ways, served this evil cause. ... That's what people do. Most people who do terrible things in the world are not madmen and psychopaths. They're people who have convinced themselves they're good, even though we can see clearly that what they're doing is a terrible thing."

In fact, Spotnitz expects a portion of the audience to actively root for Joe, even though he's one of the bad guys. "The thing that sort of saves his character is that he doesn't seem to be an ideological Nazi," Spotnitz says. "You don't get the sense that he really believes in Hitler and anti-Semitism and all those things. He seems to be somebody who just grew up there and whose father would appear to be a powerful Nazi. He's trying to win his father's approval somehow, but you don't really sense that his heart's in it. Maybe if he can come to terms with his father's approval or lack thereof, maybe he could turn to the good side."

When the story diverges from Joe and Juliana's adventures with the resistance movement, it gets bogged down in a subplot involving Japanese Trade MinisterNobusuke Tagomi (Cary-Hiroyuki Tagawa), who is navigating the cold war between Germany and Japan that he expects to heat up significantly when Hitler, who's suffering from Parkinson's disease, dies. Although the tension between the two fascist regimes gives the show a more epic scope, it can be a bit tedious until the threads all start to come together. But perhaps the strongest subplot is Frank's response to his brief, heartbreaking time in prison. Through that character's eyes, Spotnitz is able to explore the weariness that comes along with living in an occupied state and just what it takes to stand against a ruling force. As such, the show's "what if?" premise then becomes a much more personal question for the audience.

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"One of the things that haunts me about the book... is you see how similar it is to our world in so many ways," Spotnitz says. "We all like to think we'd join the resistance, but the truth is, many of us would be like the Frank, who is just trying to stay alive, just trying to protect their families, just trying to go on. You wouldn't step out of line unless you were forced to. We don't live in a fascist society, but there are things that are going on that we don't agree with. Did we step out of line? Did we inconvenience ourselves to try and make the world a better place? That's one of the great things this show says: If you want the world to change, it's up to you. And if you don't do it, don't assume the good guys are going to win because there's nothing inevitable about that. That depends on courage and sacrifice if you want the world to be a better place."

It's that notion — not the sci-fi or conspiracy elements — that Spotnitz is clearly most interested in presenting. "I don't ever want that to overshadow the characters and the other ideas - the human ideas - of the story, which I think are so rich and moving," Spotnitz says. "This is not one of those shows where you watch and in the final episode, we're finally going to tell you what the films are. That's not the point. The point is how you live in a world where everything is upside down, where things are wrong, and how you hold onto your humanity when it seems impossible."

Similarly, don't expect to meet the Man in the High Castle — who could just as easily be pulling strings in Emerald City as inspiring a resistance against the Nazis — any time soon. "It's very hard to think about him without thinking about the Wizard of Oz," Spotnitz says with a laugh. "But we don't actually meet the Man in the High Castle in Season 1, so that's an issue I'll have to wrestle with if there's a Season 2."

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And will there definitely be a second season? "I designed it to be a satisfying 10 hours, so you feel like at the end of the 10 hours, you've been rewarded for watching it," Spotnitz says. "But I definitely didn't design it to end. Wen you see the last scene of episode 10, it better not be the end — because it only raises more questions."


The Man in the High Castle's entire 10-episode first season is available now on Amazon Prime.