16-year-old Ruby Baker (Leelee Sobieski) is enjoying a night out with friends in California, but upon returning home, she is met by the sight of a police patrol car. Ruby fears the worst, suspecting her parents, David Anthony Baker (Michael O'Keefe) and Grace Heather Avery Baker (Rita Wilson), have reported her missing after her late night. Tragically, she learns that they have died in a car accident on Mulholland Drive, leading her to faint from shock. The accident is attributed to drunk driving, claiming the lives of both her parents—David, aged 45, and Grace, aged 42.
During their funeral, her younger brother Rhett Clark Baker (Trevor Morgan) struggles to hold back tears as he attempts to speak, while they are comforted by family friends Terrence "Terry" Glass (Stellan Skarsgard) and Dr. Erin Madre Glass (Diane Lane). Terry delivers a heartfelt tribute, but after the service, Ruby encounters her uncle Jack Avery (Chris Noth), who she hasn't seen in a decade. She was merely 6 years old at their last meeting, while Rhett was just a toddler.
In the wake of their parents' passing, the estate lawyer Alvin Begleiter (Bruce Dern) informs Ruby and Rhett of their substantial inheritance. Furthermore, their parents named Terry and Erin as their guardians should anything happen to them. Moving into Terry and Erin's lavish Malibu home, Ruby and Rhett find themselves amidst luxury but deal with the discomfort of Ruby sharing a room with Rhett temporarily, while they adjust to public schooling.
However, Ruby's anxiety spikes during her first driver's education class, which features a disturbing film about drunk driving, igniting memories of their parents’ tragic death. Things seem to take a sinister turn when she witnesses an argument between Terry and Erin. An uncomfortable dinner follows where Ruby feels threatened by Terry's overly familiar behavior.
A string of unsettling discoveries leads Ruby to worry about the true intentions of her new guardians. After finding Erin passed out with a syringe, Ruby attempts to reach out for help from Alvin but learns that she and Rhett would become wards of the state if their situation with Terry and Erin doesn’t improve. To her shock, Alvin reveals their inheritance is worth $4 million, far beyond what they imagined.
When Terry and Erin dismiss Ruby's concerns about Erin's supposed diabetes and their chaotic living conditions, Ruby senses something sinister. A series of covert investigations into the integrity of Terry and Erin unfolds, including Ruby's discovery of a postcard from her uncle Jack, which she hides. After finding incriminating evidence, Ruby’s suspicion grows, especially when Terry seems to be connected to the accident that claimed her parents’ lives.
As Ruby digs deeper, she uncovers Terry’s shady business dealings with loan sharks and realizes the deadly risk they all face under Terry’s neglect. When circumstances lead to Rhett being manipulated by gifts to keep him complacent, Ruby orchestrates a daring escape attempt. However, their plans are thwarted when Terry discovers their intentions, leading to a deadly confrontation.
After Ruby learns that Terry cut the brakes in his car in a desperate attempt to eliminate her and Rhett, chaos ensues. In a heart-clenching sequence of events, Terry's criminal ties unravel, leading to a confrontation that leaves multiple lives shattered. As the final showdown occurs, Ruby finds within herself the strength to confront her nightmare, leading to a dramatic turn of fate.
Ultimately, Ruby and Rhett, scarred yet resilient, lay flowers on their parents' grave, signaling a bittersweet farewell. They prepare to move in with their uncle Jack in Chicago, ready to embrace a new beginning, free from fear and danger.
