Glass Onion: A Knives Out Mystery

Andi's death was made to appear as a suicide, but it was actually murder. She had discovered that Miles Bron had stolen her original napkin concepts for Alpha and was planning to launch the dangerous Klear fuel, which could endanger lives. Hours before her death, she emailed Miles threatening to expose him. When that didn't work, someone killed her and staged it as suicide to silence her.

The film reveals early on that Andi had threatened to expose Miles, making her death suspiciously timed.

The red envelope contained the original napkin on which Andi had written the founding concepts of Alpha. This napkin proved that Miles had stolen her ideas when he ousted her from the company she co-founded. Without this evidence, Miles would have faced no legal consequences for his betrayal.

Helen mentions early in the film that Andi had told her about a crucial piece of evidence in a red envelope.

Miles forced Andi out of Alpha because she refused to support the launch of Klear, a hydrogen-based fuel that she correctly identified as dangerously unstable. Miles proceeded with the launch anyway and used her opposition as justification to remove her from the company, then warded off her subsequent lawsuit.

The film establishes early that a major disagreement over a product led to Andi's ousting.

Benoit Blanc convinced Helen to pose as her deceased twin sister because he believed Andi's killer would recognize the deception and reveal themselves. Since whoever killed Andi wanted her silence, they would react to seeing her alive and potentially make a mistake or try to finish the job.

Blanc explains his strategy early: the killer would recognize the impostor and act.

Miles Bron killed Duke Cody. During the party, Miles discovered that Duke had stolen his phone and seen incriminating evidence about the Klear launch. In panic, Miles switched Duke's drink with a poisoned one, killing him to prevent exposure of his crimes.

Duke's earlier theft of Miles's phone creates the opportunity for this murder.

Miles Bron shot Helen. After the confrontation in his art room, Miles attempted to silence Helen permanently by shooting her. However, Andi's journal that Helen was carrying absorbed the bullet and saved her life.

Miles's escalating desperation to protect his empire foreshadows his violent actions.

Miles destroyed the Mona Lisa while trying to destroy the red envelope evidence that could prove his theft of Andi's napkin. In his panicked attempt to eliminate the proof of his crimes during the mansion's collapse, he accidentally destroyed the priceless painting along with his own art collection.

The confrontation in Miles's art room sets up this desperate act of destruction.

The napkin was the original document where Andi had written the founding concepts for Alpha, the tech company she co-founded with Miles. When Miles ousted her, he used these ideas to build his empire while leaving her destitute. The napkin served as proof of her original contribution and his theft.

Andi's lawsuit loss is explained by her inability to prove her original ownership without this evidence.

Each guest had reasons to fear Andi's exposure: Lionel faced career ruin if his scientific fraud was revealed, Claire needed to hide her illegal campaign connections, Birdie faced backlash for her toxic work environment, and Duke wanted the reward money from exposing Miles. However, none of them actually killed her, Miles was responsible.

The film gradually reveals each character's secret and their potential motive.

Blanc solved the case by disrupting Miles's murder mystery game and working backwards from the threats Andi made. He realized that only someone with everything to lose, Miles, would have killed Andi to protect Klear and his stolen empire. His intervention gave Helen the space to gather evidence and confront the group.

Blanc's early interruption of the game signals his already-developing solution.

The Glass Onion mansion collapsed during the climactic confrontation between Helen and Miles. As the truth about Miles's crimes was revealed, the structurally compromised mansion crumbled around them, destroying Miles's art collection including the Mona Lisa. The guests escaped as the building fell.

The mansion's dramatic architecture foreshadows its symbolic destruction.

Klear was a hydrogen-based fuel that Andi correctly identified as unstable and potentially lethal. She refused to support its launch because she believed it would endanger countless lives. Miles ignored her warnings and proceeded, ultimately using her opposition as grounds to remove her from the company.

Andi's refusal to endorse Klear is the root of her conflict with Miles.