Glass Onion ending explained: who is the killer?

Kate Hudson, Leslie Odom Jr. and Kathryn Hahn in Glass Onion
Kate Hudson, Leslie Odom Jr. and Kathryn Hahn in Glass Onion (Image credit: Courtesy of Netflix)

After Glass Onion: A Knives Out Mystery played exclusively in movie theaters for one week at the end of November, the mystery starring Daniel Craig arrived on Netflix December 23. The sequel sees Daniel Craig's detective Benoit Blanc return to solve an all new mystery, but of course there are plenty of twists and turns along the way.

The movie centers around a group of wealthy and influential friends who are invited to the private island of tech billionaire Miles Bron (Edward Norton) to play what they believe is just going to be a murder mystery game, but when someone actually winds up dead, the hunt for the killer is on. 

In addition to Craig and Norton, the Glass Onion cast features Kate Hudson, Dave Bautista, Janelle Monáe, Kathryn Hahn, Leslie Odom Jr., Jessica Henwick and Madelyn Cline.

SPOILER ALERT, we are about to go into not only who dies and who is the murderer in Glass Onion, but other key details involving the movie's various plot twists. If you haven't watched Glass Onion yet, be sure to do that and then come back if you have any questions. But if you have seen Glass Onion and want to clear a few things up, let's dive in.

Who dies in Glass Onion?

Glass Onion: A Knives Out Mystery cast

(Image credit: Netflix)

With the presence of Benoit Blanc at this annual friends gathering on Miles' private Greek Island, the murder mystery game that was going to see Miles "killed" is quickly solved by the famed detective. However, with tensions high between many of the friends, things kick into gear when one of them ends up actually dead.

That person is meathead influencer Duke Cody (Dave Bautista), who suddenly drops dead surrounded by everyone gathered in the room. Blanc is able to deduce that Cody was poisoned from a drink that was actually intended for Miles. All of the guests' first inclination is to blame Andy (Janelle Monáe), Miles' ousted former business partner and another surprise guest on the island, but Blanc realizes everyone has a potential motive for wanting Miles dead.

When the lights go out (part of the planned murder mystery game), everyone scrambles. Blanc eventually runs into Andy, but she is shot from an unseen assailant. So now there are two dead. Were they killed by the same person? And why?

What's the deal with the Glass Onion flashback?

Janelle Monae in Glass Onion

Janelle Monae in Glass Onion (Image credit: Courtesy of Netflix)

Before we get to see Blanc work his deduction skills, a flashback sequence fills in some key details about all of the potential suspects and Andy's death. The first being that Andy did not actually die on the island.

We learn Andy has a twin sister Helen (also played by Monáe), who reaches out to Blanc after Andy's apparent suicide. Helen reveals Andy was betrayed by her former friends when she and Miles fought for control over their tech company; they supported Miles, lying that he had come up with the idea. Unconvinced she would kill herself, Helen believes instead it was one of her "s**thead" former friends after Andy told them she had found the original napkin with the plans for the company.

Blanc agrees to take the case, but seeing as news of Andy's death has not yet been shared, he wants Helen to help him by pretending to be Andy. He also says because they are not involving the police yet, he can only help her put the pieces together, he can't put anyone in jail himself. She reluctantly agrees and together they gather who would have a potential motive to kill Andy.

They learn just about everyone had a reason to want to protect Miles from Andy's discovery, but they also have their own issues with what Miles is doing. Birdie Jay (Kate Hudson) and her assistant Peg's (Jessica Henwick) careers are on the line taking the blame for using sweatshops that Miles helped them out with; Claire (Kathryn Hahn) and Lionel (Leslie Odom Jr.) are being forced to push an unstable new energy source, Klear, that Miles wants; Duke (Dave Bautista) has been rebuffed for a spot on Miles' TV network and knows about Miles sleeping with his girlfriend, Whiskey (Madelyn Cline).

But who killed Andy and who killed Duke?

Who is the killer in Glass Onion?

Kate Hudson, Jessica Henwick, Daniel Craig and Leslie Odom Jr. in Glass Onion

Kate Hudson, Jessica Henwick, Daniel Craig and Leslie Odom Jr. in Glass Onion (Image credit: John Wilson/Netflix)

Though everyone had reason to protect Miles against Andy's discovery, it was Miles who actually did the deed. After he learned about Andy finding the original company plans, he went over to her house and poisoned her, then staged her death to look like a suicide. 

It's revealed Duke knew Miles had been at Andy's before anyone else, so when the news of Andy's death finally broke online, Duke got alerts and was able to put the pieces together, so he tried to blackmail Miles for a TV spot. That's when Miles purposefully handed Duke a drink with pineapple, which Duke was allergic to, killing him. The icing on the cake is that Helen, not dead because a notebook stopped the bullet that Miles (again) shot at her, found the original napkin in Miles' office. However, Miles is able to destroy the napkin.

Though the case has been solved, Blanc says because there is no physical evidence (the napkin and Duke's eyewitness account) he can't do anything to punish Miles and none of the others are willing to go against him. So Helen decides to take matters into her own hands, smashing everything in Miles' house that is made of Klear (statues, tables, etc.). While they all think this is just a cathartic outburst, Helen actually plans to use Klear and its unstable tendencies as tinder to burn the house down. Everyone escapes the fire, but Miles' legacy is tarnished as his dream product destroyed the Mona Lisa (which the billionaire got on loan from the Louvre).

With Miles at his lowest and the police on their way, all the friends turn finally turn against Miles, promising to testify that they saw him at Andy's, allowing them to convict him for her death.

Watch Glass Onion: A Knives Out Mystery on Netflix.

Michael Balderston

Michael Balderston is a DC-based entertainment and assistant managing editor for What to Watch, who has previously written about the TV and movies with TV Technology, Awards Circuit and regional publications. Spending most of his time watching new movies at the theater or classics on TCM, some of Michael's favorite movies include Casablanca, Moulin Rouge!, Silence of the Lambs, Children of Men, One Flew Over the Cuckoos Nest and Star Wars. On the TV side he enjoys Only Murders in the Building, Yellowstone, The Boys, Game of Thrones and is always up for a Seinfeld rerun. Follow on Letterboxd.