Army Baby

In 1960 suburban America, Alice Bradford and Céline Jennings are next-door neighbors and mothers to boys of a similar age. Alice stages a surprise party for Céline's birthday. The next day, Céline's son, Max, stays home sick from school. Alice, pruning roses in her own garden, spots Max standing precariously on a balcony, trying to hang a birdhouse he made at school. Alice, realizing the danger, tries to crawl through a small tunnel-like break in the hedge separating the two properties but her large sunhat prevents her from doing so quickly. She then runs around the hedge to reach the front door and attempts to alert Céline, who is inside vacuuming. The two are unable to act quickly enough and Max falls to his death. After her son's death, Céline distances herself from Alice, but grows closer to Alice's son, Theo. At Max's funeral, Theo notices one of his own toys in Max's coffin and lashes out. After the funeral, Céline leaves for an unknown location for a month, and when she returns, she reconciles with Alice. One day, Alice leaves Theo with Céline at her house and she sees Theo playing with bubbles on the same balcony Max fell from. She panics and runs to him, but this time she crawls through the passageway in the hedge and immediately gets near to Céline's house. Céline appears beside Theo, explaining she was watching him, but she quickly noticed Alice could get through the hedge for her own son, unlike the last time for Max. Alice also notices that and thinks the incident was Céline's attempt to test her. Theo grows even closer with Céline, to the point of inviting her to his birthday party, much to Alice's dismay. The party goes as expected, but afterward, Alice's mother-in-law (Simon's mother) suddenly collapses, dying of a heart attack. Simon's mother has been taking medication for her heart, but an autopsy carried out at Alice's request reveals no trace of that medication in her bloodstream. Alice suspects that Céline has been replacing the drug with a placebo, but her attempts to find evidence prove fruitless. Alice's suspicions deepen when Theo is hospitalized after a severe allergic reaction at Céline's house, with Alice believing Céline has deliberately encouraged Theo to eat food to which he is allergic. Alice enters Céline's house while she is out one day to attempt to find evidence, but Céline catches her and orders her to leave. Alice and Simon contemplate moving away from Céline, but the two eventually reconcile after Theo threatens to take his own life in response to their feud. Later that night, Céline kills her husband by sedating him with chloroform and slicing his wrist, making it look like a suicide. Alice and Simon allow a seemingly distraught Céline to stay with them, but while Alice goes to Céline's house to gather the rest of Céline's things, Céline sedates Simon and Theo. When Alice discovers this, she and Céline fight. Alice initially fends off Céline's attempt to forcibly sedate her, but Céline later does succeed in sedating her and killing both her and Simon by disconnecting their boiler to stage a gas leak. She spares Theo and later adopts him.