‘Glass Onion: A Knives Out Mystery is a Rian Johnson-directed whodunnit that is a sequel to 2019’s ‘Knives Out’. It takes Detective Benoit Blanc (Daniel Craig) to a private island in Greece, where he starts unfurling the layers of a larger mystery after a murder is committed.
Warning: This article contains heavy spoilers
Glass Onion opens during the COVID-19 pandemic and introduces scientist Lionel Toussaint (Leslie Odom Jr.), Connecticut Governor Claire Debella (Kathryn Hahn), fashion designer Birdie Jay (Kate Hudson), and men’s rights streamer Duke Cody (Dave Bautista).
They all receive a puzzle box from their billionaire friend Miles Bron (Edward Norton), CEO of Alpha, a technology company. They solve their respective packages together on a conference call and find an invitation to spend a weekend on Miles’ private island in Greece.
Meanwhile, two other invitations go out to Miles’ former partner at Alpha, Cassandra “Andi” Brand (Janelle Monáe), and Detective Benoit Blanc.
Everyone meets in Greece and gets on a two-hour yacht ride to the island. Lionel, Claire, Birdie, and Duke are surprised to see Blanc among the guests and shocked by Andi’s arrival. They are also accompanied by Birdie’s assistant Peg (Jessica Henwick) and Duke’s girlfriend Whiskey (Madelyn Cline).
Unfortunately, Andi was pushed out of Alpha by Miles after a disagreement between the two, and she recently lost the lawsuit as well. At the island, Miles greets everyone and is slightly taken aback after seeing Andi.
He takes them on a tour of his mansion, called the Glass Onion, and reveals that he plans on hosting a murder mystery game over the weekend. Curiously, he takes Blanc aside and questions his presence.
It is revealed that Miles never invited Blanc, but someone among the guests might have reset the box and sent it to him as a gag. Seeing the fun of having a detective around for his party, Miles formally invites him on the spot.
He then shows Blanc a piece of napkin on which he wrote the idea for Alpha years ago. He mentions that it was from an old bar also known as the Glass Onion, which used to be their favorite hangout place.
As the group settles in, they spend time at the swimming pool, where Blanc familiarises himself with everyone. He finds that Duke always carries his pistol with him, Birdy is being told to make a problematic statement in front of the press, and Whiskey is having a secret affair with Miles.
During a conversation with everyone, Andi finally loses her cool and criticizes the group for betraying her and supporting Miles because he helped them financially in their respective endeavors.
That night at dinner, Miles shows off his art collection, including the Mona Lisa, which he has borrowed from the Louvre for a short time. He expresses his desire to create something so relevant that his name is immortalized like the famous Da Vinci painting.
This is when he mentions Alpha’s latest project, a hydrogen-based alternative fuel named Klear. He presents Blanc with a small sample, but Lionel and Claire panic. The former is the lead scientist at Alpha and strongly condemns the fuel as it is potentially dangerous.
Miles asks him to calm down and reveals that his entire island is powered by it, proving its efficiency. As they begin to eat, he explains the rules of the game, but Blanc solves a weekend’s worth of puzzles in a couple of minutes.
The host is infuriated and takes Blanc to his office. The detective reveals that he deliberately ended the game quickly as he fears for Miles’ life. Blanc explains that he knows that each of his friends has the motive to hurt the billionaire.
This game might put the idea of murder in their heads, almost like handing a potential killer a loaded gun and turning off the lights. Miles doesn’t believe that his friends can hurt him and goes back to liven the dull mood.
Just as he convinces everyone to start drinking again, Duke starts choking, falls over, and dies. Blanc takes control and asks Lionel to radio for boats and the Police. Things go from bad to worse when Miles realizes Duke died after drinking from his glass.
He panics and hides behind the detective, convinced that someone among his friends tried to kill him and narrowly missed. Blanc notices that Duke’s gun and phone are missing, triggering more hysteria. Eventually, the clock strikes 10 pm, and the lights go out.
This was supposed to be a part of the mystery party but now turns into a dangerous situation. Blanc goes to find Andi as she had left the room due to an argument with everyone before Duke died.
He finds her outside, and they quickly discuss something before someone shoots Andi and kills her. Mortified, Blanc gathers the remaining guests back inside and starts unpeeling the layers of this mystery.
Glass Onion: A Knives Out Mystery ending explained in detail:
Who hired Blanc?
The plot switches to a flashback, and it is revealed that Andi committed suicide days before the island gathering. Her twin sister Helen was investigating her house when the puzzle box was delivered. She opened it with a hammer and took it to Blanc.
Blanc and Helen discussed the case, and the latter believed that Andi was murdered. She showed the detective a sent email from Andi’s account that had a picture of a red envelope addressed to Lionel, Claire, Birdie, and Duke.
There was also a message that stated that she finally found some critical evidence, and she’d use it to burn Miles’ empire down. Helen pointed out to Blanc that no one replied to that email, and the next day Andi died. Furthermore, the red envelope was missing.
Blanc suggested that Helen accompany him to the island as Andi and help him investigate the case. Since the news of her sister’s death wasn’t out yet, no one would suspect her.
They met in Greece a day before the weekend and went over Andi’s journals. Helen explained that this group used to hang out at a bar called the Glass Onion years ago. Andi introduced Miles to the group and wrote the idea for Alpha on one of the bar’s napkins.
The duo saw immense success together, but when Miles got obsessed with Klear, Andi walked out with 50% of her company, sensing the dangers of this compound. Unfortunately, Miles used clever legal moves to push her out of Alpha and convinced all their friends to side with him.
Everyone testified Miles wrote the idea for Alpha on the napkin, and Andi couldn’t prove otherwise since she did not keep the original with her.
After losing the lawsuit, she broke her bookshelf out of frustration and found the real napkin. That is what the red envelope contained, and Andi threatened to expose the truth before she was killed.
Helen suspects one of the five killed Andi.
What did Blanc and Helen discover on the island?
As soon as they reached Miles’ island, Helen started snooping around as Blanc befriended the group. She had a conversation with Whiskey that revealed Miles surprised her for her birthday, confirming that he wasn’t in Greece this whole time like he claimed to be.
Furthermore, Duke wanted to be on Alpha News and was using Whiskey to seduce Miles into giving him the spot. Furthermore, Lionel and Claire had risked their professional reputations to support Klear, despite knowing how dangerous it was.
The plot finally reaches the point where Helen (As Andi) chastises everyone after having a few drinks of hard kombucha. Once she walked off, she was confronted by Claire and Duke, who revealed that they did not answer the email but called and even came to visit her.
However, her house was locked, and no one was around, so they left. This was new information for her, so she shared it with Blanc. Also, Birdie’s sweatpants company was funded by Miles, but she made a mistake when she positively reacted to the news of her clothing being made in a Bangladeshi sweatshop.
She misunderstood the meaning of sweatshop, and Miles wanted her to take the blame for it so that his reputation as an investor could be saved. He promised her handsome payment in return.
Finally, Blanc finished the game quickly and instructed Helen to argue with people after dinner. This allowed her to leave and search everyone’s rooms for the envelope. Whiskey saw her and thought she was responsible for Duke’s murder.
That is why Blanc went to look for her when the lights went out, but she was shot before they could discuss anything further.
Who killed Andi?
Fortunately, Helen doesn’t die as presumed earlier. She is saved due to the bullet hitting Andi’s journal in her pocket. However, Blanc sees this as an opportunity and instructs Helen to play dead. He takes the others inside and tells her to search Miles’ office for the napkin.
Meanwhile, Blanc starts revealing the secrets of the case, and as it turns out, Miles is the killer. Blanc exclaims he thought it would be a deeply clever and convoluted case, but the answer was simple and in front of him the whole time.
He mentions that Miles was in America, surprising Whiskey for her birthday when Lionel sent him a fax of Andi’s threatening email. So, he went to her place and killed her.
Furthermore, he also killed Duke that night because the news of Andi’s death had finally broken, and he used it to blackmail Miles for a spot on Alpha News. This is because when Duke went to see Andi, he saw Miles leaving in his car.
So, after dinner, Miles poured pineapple juice into his drink, handed Duke the glass, and triggered his severe allergy to the fruit. In the chaos that followed, he also stole his phone and gun.
This is when Helen walks in with the envelope she found in Miles’ office, and the group realizes that Andi is dead. Miles just scoffs at the whole situation and reveals that they have no proof.
Helen, however, states that Andi’s napkin has the Glass Onion logo on it, whereas the one he claims to be the original does not. Miles is stumped but acts quickly and burns the napkin with his lighter.
Blanc is furious but confesses that he cannot prove Miles’ guilt without evidence. Helen turns towards the others, and they still take the billionaire’s side. Blanc apologizes but subtly hands Helen the tiny Klear prototype that Miles had given him before.
To vent her frustration, Helen starts smashing the art collection pieces and sets the bar on fire. Fortunately, the others join in. As the sprinkler system activates, she throws the Klear piece into the flames, causing the whole mansion to explode.
Miles is shaken to the core, and Helen makes sure the Mona Lisa burns as well. With Miles’s reputation ruined due to the painting’s destruction and Klear being proven dangerous, the group agrees to testify against him.
Helen and Blanc sit on the beach as they watch the police boats arrive.