'Glass Onion' spoilers! Why the 'Knives Out' sequel went all in for that fiery ending

Spoiler alert! The following post discusses important plot points, the ending and, of course, whodunit in “Glass Onion: A Knives Out Mystery” so beware if you haven’t seen it yet.

The case is closed, a murder solved and a villain got his comeuppance in writer/director Rian Johnson’s latest “Knives Out” mystery. However, there was one major casualty that will raise (and singe) some eyebrows.

Daniel Craig’s Southern detective Benoit Blanc returns in the sequel “Glass Onion” (streaming on Netflix now) and travels to a private Greek island where tech billionaire Miles Bron (Edward Norton) has gathered his friends – politician Claire (Kathryn Hahn), influencer Duke (Dave Bautista), fashionista Birdie (Kate Hudson) and scientist Lionel (Leslie Odom Jr.) – for a murder mystery getaway.

'Glass Onion' review: New A-list whodunit is bigger, not better than masterful 'Knives Out'

Who dies in 'Glass Onion'?

Miles is the sort of rich where he buys things just because he can, and in his glass man cave he shows his crew that he’s rented Leonardo da Vinci’s actual Mona Lisa. It’s symbolic for Miles: He’s long said he wants do something that will make him immortal and spoken in the same breath as that piece of art, and Miles is on the cusp of announcing to the world a game-changing new hydrogen fuel.

The billionaire’s ex-business partner Andi (Janelle Monae) also shows up, and the game's afoot from there. Blanc ruins Miles’ big party plans, Duke winds up dead, Andi’s revealed to be her twin sister Helen – because Andi was murdered a week earlier – and Helen’s there to catch the killer alongside the detective. Ultimately, Miles is revealed as the culprit, who made Andi’s death look like a suicide, and he burns up the evidence that would have made things right for her sister (after Andi was forced out of their Amazon-esque company).

Explain the ending of 'Glass Onion'

An angry Helen begins destroying Miles’ possessions, creates a huge blaze thanks to his unstable hydrogen fuel and, to Miles’ horror, smashes the lever that leaves the Mona Lisa unprotected from the fire, burning up the artwork. The act guarantees that Miles will definitely be infamous but also ruined, with his remaining pals turning on him as police boats show up.

Peeling the 'Glass Onion': How the new 'Knives Out' mystery switches up the usual suspects

Johnson’s goal from the beginning was “could we pull this off where we burned the Mona Lisa to a crisp at the end and get a round of applause from the audience,” Johnson tells USA TODAY. “On the one hand, it is the most famous, revered work of art in the world and the other hand, it exists as an object. So much so that the audience gets the joke immediately: It's so much of a sacred cow, it’s not a sacred cow.”

A friend of his brought up a poll that asked people if the Mona Lisa burned in a fire, would they rather stand in line to see a perfect replica or the charred ashes of the original? “Overwhelmingly, people answered they'd rather see the ashes,” Johnson says. “I don't know what it means, but it's very interesting.”

What was the big challenge for director Rian Johnson?

Another major challenge for the filmmaker was pulling off the Helen reveal, which happens at the midpoint of the movie and essentially rewinds the movie to play what’s happened thus far from the twin sister’s perspective. “Could you do the fugue structure basically where you layer it back over itself and have it be compelling, as opposed to making everyone's shoulders sag and think, ‘Oh, we have to watch all this again,’” Johnson says.

But that twist emotionally involves the audience “in a way that straps a rocket pack onto it narratively for that second half,” the filmmaker adds.

Johnson reasons that murder mysteries are comforting to movie lovers – but maybe not, at least in this case, Mona Lisa-adoring art aficionados – because “there's moral chaos created at the beginning with a crime and the detective comes in and puts the universe right by the end of it, by finding the truth,” Johnson says. “We don't do exactly that in these movies, but there's a moral equilibrium by the end of both ‘Knives Out’ and this movie that Blanc puts back into place.”

The director feels the frequent popularity of murder mysteries speaks to their times, be it the golden age of detective fiction in the 1930s, the nostalgic wave in the late ’60s and ’70s, and also right now.

“You could make the argument that that kind of fairy tale of moral certainty winning out at the end of the day is incredibly appealing in times where we feel like we're all kind of searching for that in the world,” Johnson concludes. “I also just think these stories come back into vogue every few decades because people remember how much fun they are.”

This article originally appeared on USA TODAY: 'Glass Onion' spoilers: Janelle Monáe makes a fiery decision in sequel