Dishonored 2 is the second half of an incomplete story, not a sequel that exists purely as a business proposition. Arkane Studios came out of Dishonored with much more to say about the follow-up's new playable protagonist, Emily Kaldwin.

"Emily in the first one was really an anchor to the world," Arkane co-founder and Dishonored 2 co-director Raphael Colantonio told Mashable at E3 2015. "There was not much worth saving other than her. So she became really interesting to us."

Emily is the daughter of the late Empress Jessamine Kaldwin, who was assassinated at the start of Dishonored. She's a key character in that first game. The hero of the story, bodyguard-turned-assassin Corvo Attano, also happens to be her father. She ends up under his protection after he rescues her from kidnappers, and she becomes a sort of moral barometer for the game's mute protagonist.

"She's special because she's watching you. If you play very violently, she changes in the game. So people were interested in Emily," sequel co-director Harvey Smith said.

"You have this privileged girl who, instead of living the life she would have lived, got interrupted by this tragic event. But then she was raised by Corvo the rest of the way. So who would she be as an adult?"

Dishonored 2 aims to explore Emily's adult existence. It kicks off 15 years after the events of the previous game, with a mysterious invader arriving to usurp the young empress. Emily escapes and goes into hiding, with the intent of meting out vengeance from the shadows just like dear old dad.

"There were a bunch of pitfalls to avoid," Smith said of incorporating Emily into the story as a playable character. "Obviously there are a bunch of tropes that people lazily reach for when they make female protagonists. But we worked really hard. Our narrative designer, Sachka Duval, was involved in that. It's been a good process."

Emily isn't the only playable character. Corvo is back as well, and it's up to players to decide which one to inhabit. There's a catch, though: the choice is a one-time deal. You can't switch back and forth from mission to mission. You pick between Emily and Corvo early in the game and that's the end of it.

"We were trying to decide how ... to break it up so you make the choice," Smith said. It was the game's lead level design director, Christophe Carrier, who came up with what turned out to be a perfect solution.

Smith continued: "He's the one who recommended, maybe you play as Emily for like half an hour and then you get to this pivotal moment where a dramatic thing happens, and you choose at that point whether to continue with Emily or switch to Corvo. And then you're locked in."

The two characters have completely different sets of powers, but the missions they embark on are the same. Much like the first game, variety stems from how you trick out your chosen character's skill tree, since you can't unlock everything in a single playthrough.

"Emily fights with a little more finesse than Corvo does," Smith said. "Whereas Corvo has the very classic Possession, Rat Swarm, Blink [abilities], Emily has Far Reach, Shadow Walk, Mesmerize... these powers that nobody has heard of."

Smith points to Far Reach, which Dishonored 2's cinematic debut trailer conveyed a sense of. "You send this magic tendril out into the world to pull yourself to a location," he said. It's Emily's stand-in for Corvo's own Blink ability, which teleports the assassin short distances.

Emily's power evolves differently, however. "You can stick to walls, you can yank somebody toward you and assassinate them in mid-air, so you have these synced assassinations in mid-air," Smith said. "It begins to feel different, and it adds momentum. You can run and jump and it has rope physics to it."

Who you play as influences more than tactics, however. Emily and Corvo are both fully voiced this time, and that has a direct impact on the story. Not so much the main beats; more how you, the player, perceive the world as you move through it in one character's shoes versus the other's.

"There's a different theme in the narrative sense, in the literary sense," depending on which character you roll with, according to Smith. "Corvo's an older guy, he's coming home for the first time to Serkonos. Emily is like an empress outlaw on the run, and she's young, she's 25. So their perspectives are very different."

None of this would be possible without the groundwork laid by the first game. Dishonored has the feel of a steampunk Victorian-era London setting, but it's not set in a world we know. The distinct sense of place that the game conveys is a product of Arkane's creative process.

"There's a little saying at Arkane, that we make our worlds bigger than the game," Colantonio said. "Every element, you feel like it's actually referring to something that is not really in the game but makes the game feel stronger, more real.

"It's [also] tempting for us to then go exploring and tell more about those other pieces. So it's the world that creates itself."

Smith readily admits that Dishonored development was at roughly the halfway point when the decision was made to separate the game's fictional Dunwall from Earth. "The year kept changing. The costume styles. It kept drifting forward," he said.

For Smith, the emphasis on world-building is a product of his own interests, going all the way back to his childhood appreciation for the award-winning sci-fi/fantasy author Roger Zelazny.

"When I was a kid he was one of my favorite fantasy writers. And he said that for every fiction he did, he wrote some extra chapters," Smith said. The short pieces of writing served to bridge the events that occured between chapters, lending additional detail to the world.

"And then he would burn that chapter," Smith said. "He would literally tear the pages up. He said he did it [because] it deepened his understanding of the world and what the character was doing in that sequence of time."

The same is true for Arkane's relationship with the original Dishonored. "We know things about what was going on that day [when Empress Kaldwin was assassinated]," Smith said. "Why was that guard yelling at that other guard? Even if it changes a little later, even if we forget it, even if it never comes into the game, it really influences our thinking.

"And you can feel that. You can't articulate it because it's not literally there, but you can feel it somehow."

Dishonored 2 comes to PC, PlayStation 4 and Xbox One sometime in 2016.