Spoiler alert! We're discussing the ending of "Rebel Moon" (streaming now on Netflix). Kindly stop reading if you don't want to know.

Charlie Hunnam's scoundrel Kai has opted out of joining the "Rebel Moon" uprising in true traitor style.

The mercenary pilot, who described himself as an "opportunist" to rebel leader Kora (Sofia Boutella), did the ultimate movie nasty at the end of "Rebel Moon - Part One: A Child of Fire," the new sci-fi epic directed and co-written by Zack Snyder.

Kai took the rebellion's money to shuttle around the galaxy in his Tawau-Class freighter so Kora could pull together an Avengers-esque crew of warriors to fight the oppressive Imperium: General Titus (Djimon Hounsou), Nemesis (Bae Doona), Tarak (Staz Nair) and Darrian Bloodaxe (Ray Fisher).

The roguish Kai started to show a heart of Han Solo gold, even promising Kora to fully join the motley crew's fight and be "honorable." But it was all to set a trap and turn the suddenly-restrained rebels over to the Imperium and Admiral Noble (Ed Skrein), earning Kai a life-changing bounty.

"My job was to make you like Kai, to make you learn to trust him and want him to be part of all this," Hunnam tells USA TODAY. "This betrayal is only impactful if it's surprising."

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Snyder, who originally pitched "Rebel Moon" to Lucasfilm as a "Star Wars" film before seeking the creative freedom of Netflix, says Kai went "dark Solo."

Hunnam, 43, literally asked for it, insisting on playing Kai as opposed to any other character in the expanding Snyder-verse. "I didn't want somebody else playing Kai and thinking he was a bad guy," the actor says. "I see him exactly as he wants to be played."

Hunnam was so protective of the character that he's still smarting over what he sees as the film's failure to fully account for Kai's betrayal.

"There was a version that absolutely broke my heart as Kai explains that his whole family had been killed. And that taught him to never set foot on the wrong side of history," says Hunnam. "There's a lot on the cutting room floor. I reached out to Zack and begged him to put that back. I don't know this character unless he gives his history and gives the audience just a tiny opportunity to understand what motivated him."

Does Kai die in 'Rebel Moon'?

Speaking to the restrained Kora, Kai does reveal how the Imperium destroyed his world and taught him to stand with the heavy favorite (and get rich doing it).

"In this ultra-authoritarian regime, he wants some sort of autonomy and control over his life," says Hunnam. "And he's willing to compromise his moral North Star to survive."

But the plan backfires when Kai instructs Gunnar (Michiel Huisman) to shoot Kora, who is beloved by the rebel farmer. Instead, Gunnar quickly shoots Kai in the head. In the ensuing battle, most of the warriors escape, but Bloodaxe has a seemingly heroic death taking out an enemy ship.

Kora prevails in her eventual one-on-one showdown with Noble, plunging him to certain death into rocks. Yet Noble is rejuvenated by the movie's end for a rematch in "Rebel Moon − Part Two: The Scargiver" (April 19 on Netflix).

Hunnam insists Kai could still be in "Part Two," despite his mortal head injury.

"Noble gets his skull crushed and falls 2,000 feet on rocks and he's alive," says Hunnam. "How do we even know Kai's dead? We don't see a body."

Snyder confirms Kai's demise. "Oh, yeah, he's definitely done," he says. But the director hints another character might have survived a deadly battle blow. "Bloodaxe, we don't know about," he says without elaboration.

How many 'Rebel Moon' movies will there be?

"Rebel Moon" is a fast-expanding universe. "Child of Fire" and "Scargiver" were shot simultaneously, and the second film is already "99% done," Snyder says.

"Scargiver" will bring the battle back to Kora's adopted home, the farming planet of Veldt. The movie will explain how Kora earned her Scargiver nickname against the oppressive Motherworld, the planet on which the Imperium is based. "She's made an emotional wound on the Motherworld. That will be revealed," says Snyder.

While a planned third film hasn't been officially greenlit, Netflix has purchased Snyder's outline script, he says. The film will finally show the Rebel Moon of the franchise's title.

"Veldt is a moon. And there are rebels on it. So the 'Rebel Moon' title works for the first two movies," says Snyder. "But the actual thing that the Motherworld calls the 'Rebel Moon' won't be seen until the third movie."

Snyder envisions multiple follow-up films. "Six films is what I'd be comfortable with," he says.

When will we see the R-rated, extended director's cut of 'Rebel Moon'?

Snyder is known for director's cuts of movies such as "Justice League," which he released after disagreeing with studio-mandated changes. Each "Rebel Moon" installment will have R-rated director's cuts coming out around summer 2024, he says. But the "Rebel Moon" extended cut did not spring from studio conflict. It was Netflix's idea.

"Netflix suggested from the beginning, make two versions," says Snyder. "It's almost like an alternate universe. One that's more insane. One that's a little bit easier for everybody."

The director wrote the original script as an "adult, hard-R" movie. So he reveled in making the second versions, which will add an hour of material to each movie with more vicious battles. In the alien brothel scene, for example, "there's a whole different vibe," Snyder says. "The movie is much more sexual, more violent, more Heavy Metal magazine."