Mothers' Instinct

Alice stages a surprise party for Céline's birthday in the suburban street. The gathering reveals the uneasy balance between the two families and foreshadows the creeping tension that will drive the plot. The event introduces the neighbors' fragile dynamic that will soon fray under tragedy.

Max stands precariously on the balcony trying to hang a school birdhouse. Alice spots him from the hedge and frantically tries to warn him, but her sunhat slows her progress. Max falls to his death, a tragedy that binds the two families in grief.

Max's funeral becomes a focal point of the mounting tension between the neighbors. Theo notices a toy of his own inside Max's coffin and lashes out in grief. The moment crystallizes how grief exposes hidden loyalties.

In the wake of Max's death, Céline pulls away from Alice and forms a tighter bond with Theo. Alice feels paranoid and betrayed as the neighborly trust unravels. The rift settles into a dangerous competition over the boy's attention.

Céline leaves for an unknown location for a month, leaving Alice and Theo unsettled. When she returns, she reconciles with Alice and the two families resume a tense, uneasy coexistence. The disappearance heightens questions about Céline's motives and the stability of the neighborhood.

Alice leaves Theo with Céline and later sees Theo playing on the balcony where Max fell. She panics and crawls through the hedge passage to reach Céline's side. Céline reveals she was watching, and notes that Alice could traverse the hedge, implying she may be used as a test.

Theo grows closer to Céline, inviting her to his own birthday party. This inclusion alarms Alice, who fears Céline is gaining influence over Theo. The party becomes a battleground for loyalties between the two mothers.

During the party, Alice's mother-in-law collapses and dies of a heart attack. The tragedy adds gravity to the already fractured relationships. An autopsy later raises questions about the medication she was taking.

The autopsy reveals no trace of the heart medication in the mother-in-law's bloodstream. Alice suspects Céline has substituted a placebo, deepening her paranoia. Without solid evidence, she remains on edge.

Theo is hospitalized following a severe allergic reaction at Céline's house. Alice suspects deliberate poisoning or manipulation, and the incidents intensify the feud between the two families. The hospitalization becomes a turning point in the confrontation.

Alice sneaks into Céline's house hoping to find evidence, but Céline catches her and orders her to leave. The intrusion marks a dangerous escalation in their conflict and shows how far Alice is willing to go for Theo's safety.

Theo threatens to take his own life in response to the escalating feud. This shock compels Alice and Simon to reassess their stance toward Céline and to reach a fragile, uneasy reconciliation. The family dynamics become precipice of collapse or repair.

Céline sedates her husband with chloroform and slices his wrist, making it look like a suicide. The act demonstrates her willingness to manipulate and destroy to maintain control. The murder marks a crucial turning point in the downward spiral.

Alice and Simon agree to let Céline stay while she collects her things, but Céline uses the moment to sedate Simon and Theo. When Alice returns, a confrontation erupts as she confronts Céline about her actions.

Céline manages to sedate and kill both Alice and Simon by disconnecting the boiler, staging a gas leak. She spares Theo and ultimately adopts him, completing her malicious takeover. The neighborhood is left in shock at the final betrayal.