Sissy

During a confrontation at the lake, Alex steals Cecilia's phone and posts a damaging video "exposing" her as cruel and sadistic to her followers. When they struggle for the phone, Cecilia strikes Alex with a rock in a panic, knocking her unconscious. This moment triggers Cecilia's violent breakdown, connecting to unresolved trauma from childhood when Alex relentlessly bullied her.

Earlier, Fran mentions Alex will attend the party, and the kangaroo accident triggers disturbing visions of Cecilia's childhood tormentor.

After burying what she believes is Alex's body, Cecilia livestreams a meditation session over the grave. Jamie unexpectedly discovers her in this disturbing act and runs away in horror. Fearing he will become a witness to her crimes, Cecilia pursues him and pushes him off a cliff to ensure his silence.

The earlier scenes show Cecilia becoming increasingly isolated as the guests neglect her and mock her.

Tracey confronts Cecilia about knowing what really happened between her and Alex. Rather than risk being exposed, Cecilia shoves Tracey into the bathtub and watches passively as she drowns after her hair becomes tangled in the drain. This act demonstrates Cecilia's complete descent into cold calculation to protect her secrets.

Tracey admits she is aware of the events between Cecilia and Alex, foreshadowing her doom.

After Fran picks her up while she's driving to find Emma, Cecilia confesses their friendship drifted and laments they didn't grow old together as promised. In a sudden violent impulse, she accelerates and brakes abruptly, flinging Fran through the windshield. She then deliberately runs over his head, perceiving it as ending his suffering, but this act appears driven by her psychological deterioration rather than genuine mercy.

Fran's casual mention of Alex attending the party earlier sets the chain of events in motion.

Alex actually survives the rock strike to her head. Though unconscious and severely injured, she crawls out of the grave she was buried in. Later, she encounters Emma, who she mistakes for Cecilia due to her injuries and confusion, and attacks her in a fit of rage, ultimately being shot by police who believe she is the aggressor.

Cecilia notes Alex is still breathing briefly before burying her, though she panics and does not verify death.

When Alex crawls out of her grave severely injured, she is disoriented and delirious. She encounters Emma in the chaos and mistakes her for Cecilia, believing she is confronting her former victim. In a rage-filled state, Alex bludgeons Emma before police arrive and fatally shoot her, believing she is the sole aggressor.

Alex's violent history with Cecilia as her childhood victim establishes her mistaken identity motivation.

While burying Alex's body, Cecilia takes her necklace as a trophy or memento. Later, when Emma discovers the necklace on Cecilia, she immediately realizes something is wrong, this physical evidence helps Emma identify Cecilia as the true perpetrator behind the violence.

The necklace is taken during the burial scene, establishing it as important evidence.

As children, Alex systematically bullied Cecilia, tormenting her relentlessly. This childhood trauma remained buried but resurfaced when Cecilia unexpectedly encountered Alex again as an adult. The confrontation at the lake, combined with Alex's mocking and the posted video, triggered a psychological break that unleashed buried resentment into violent action.

The kangaroo incident triggers visions of Cecilia's childhood tormentor, and Emma calling her "Sissy" causes visible discomfort.

As children, Cecilia and Emma made a heartfelt pact to remain best friends forever, promising to grow old together. This childhood promise haunts the adult Cecilia, who feels betrayed when Emma drifted away and invited her childhood bully to the wedding. The theme of broken friendship promises drives Cecilia's later claims about wanting to "repair" their bond.

The film's opening establishes this pact, and Cecilia's lament about not growing old together mirrors the broken promise.

After burying what she believes is Alex's dead body, Cecilia begins a live stream attempting to lead followers in a meditation session while simultaneously planting a tree over the grave. This bizarre act reveals her severe psychological disarray, she attempts to maintain her influencer persona while committing murder, showcasing the disconnect between her curated online identity and her violent actions.

The contrast between her influencer lifestyle and the traumatic events has been building throughout.

"Sissy" is the childhood nickname Emma used for Cecilia when they were best friends as children. When Emma reunites with Cecilia at the pharmacy and affectionately calls her "Sissy," it causes visible discomfort for Cecilia, revealing the complicated, painful history beneath their seemingly nostalgic reunion.

This nickname and Cecilia's reaction hint at the complex, troubled history between the characters.

Cecilia survives the massacre and rebrands herself as a survivor of the "Alex Kutis Massacre," using her platform to promote a book about her "experiences." This bleak ending shows her manipulating the tragedy for personal gain without showing remorse, serving as a sharp critique of influencer culture and how people exploit trauma for profit.

The meta notes establish the film as satire of influencer culture, with Cecilia's ending fulfilling this theme.