Diane Sherman experiences the heart-wrenching trauma of giving birth prematurely, leaving her to gaze at her newborn, confined to an incubator and surrounded by a dedicated team of hospital staff. Fast forward seventeen years to Pasco, Washington, where Diane takes on the role of both mother and caretaker of her daughter, Chloe, who is confined to a wheelchair due to several chronic illnesses, including arrhythmia, hemochromatosis, diabetes, and paralysis. Gifted in technology and engineering, Chloe waits anxiously for an acceptance letter from the University of Washington. Although Diane claims to be enthusiastic about Chloe's potential independence, she is frequently obstructive, preventing Chloe from accessing the mail.
One day, while rummaging through a bag of groceries, Chloe discovers green capsules that were prescribed to her mother. Diane later administers one of these pills to Chloe as part of her daily medication routine, stating it’s Trigoxin that Chloe requires. However, curiosity gets the better of Chloe when she covertly examines the prescription bottle, only to find a label with her name obscuring the one with Diane's. Her attempt to research Trigoxin is thwarted when their home internet is down. Undeterred, she calls a stranger for help, who explains that Trigoxin is typically used for heart issues, distinguishing it as a red capsule, vastly different from what she has.
Chloe requests a trip to the movies with her mother, but her instincts drive her to the pharmacy during their outing, where she inquires about the mysterious green pill. The pharmacist reveals it's a muscle relaxant prescribed for dogs, potentially dangerous to humans, especially given Diane's false claims about its necessity for a non-existent pet. In a moment of crisis, Chloe suffers an asthma attack, leading Diane to intervene with a sedative under less-than-ideal conditions, keeping her actions hidden.
After waking to find herself confined to her bedroom, Chloe discovers she has been isolated—her mother has sabotaged the phones and her wheelchair's mobility. Summoning her strength, she escapes the house but is gravely injured while attempting to signal for help from a passing mailman. Tragically, Diane arrives just in time to prevent her from getting assistance, resorting to violence and killing the mailman.
Chloe regains consciousness in a basement, chained to her wheelchair and surrounded by shocking evidence of her mother’s deception: her college acceptance letter lies discarded in the trash along with photos revealing that Diane’s biological daughter had perished two hours after birth, leading her to abduct Chloe, who had been able to walk years prior. When Diane attempts to mend their relationship and starts offering a clean slate, Chloe confronts her mother about the abuse of a condition known as factitious disorder imposed on another, questioning the sincerity of Diane’s motives. Under pressure, Diane produces a syringe filled with a toxic substance she had been concocting, leading to a tense confrontation.
Fleeing into a storage area, Chloe consumes a bottle of organophosphate that puts both of them at risk and necessitates Diane’s rush to the hospital. Once there, Chloe finds herself trapped in a precarious state, intubated and unable to voice her experience, while Diane manipulates emergency protocols to whisk her away before she can explain her ordeal. As they navigate a tense escape on a stopped escalator, Chloe finds a moment of defiance, exercising her physical capability by moving her feet to halt her chair, just as a vigilant nurse alerts security about Chloe's disappearance.
The tension escalates when Diane brandishes a gun at the arriving officers, culminating in a chaotic shootout that leaves her injured and tumbling down the stairs.
Seven years later, although Chloe still relies on her wheelchair with limited use of her legs, she has forged a new path for herself, achieving marital and professional success in developing prosthetics for children. She regularly visits Diane, who remains bedridden in prison, recounting her life updates. Just as she prepares to leave, Chloe staunchly reveals a cunning ploy by spitting out the very same muscle relaxants Diane had once given her, asserting, > "I love you, Mom; now open wide." This haunting farewell encapsulates the twisted nature of their relationship, combining love, manipulation, and a shared history steeped in deception.
