Former U.S. Army medic and recovering addict, Jill Adams, finds herself working as a security guard at a local college, where she resorts to stealing drugs from the research lab for sale. After her shift, she picks up her children, Noah and Matilda, from their grandmother, Doris. However, their troubles escalate when their car unexpectedly loses power and is struck by another vehicle, sending it crashing into a lake. While Matilda nearly drowns, she is miraculously revived by a police officer who reveals that a widespread electrical failure is causing chaos.
At the hospital, the disturbing news sets in that coma patients have inexplicably awoken, adding to the surreal atmosphere of the town. Once they return home, Jill and her family struggle with sleeplessness, and Noah claims to see shooting stars, which Jill rationalizes as satellites. On her way to work, the situation becomes clearer when psychiatrist Dr. Murphy informs her that the residents can no longer fall asleep, leading to impending sleep deprivation symptoms. He mentions a solitary old woman under study at a military base known as The Hub, believed to be the only exception to this phenomenon.
Panicked at the thought of losing Matilda to experiments, Jill races home to find her daughter, only to discover she's at a church where the pastor is preaching about her as a beacon of hope. As Jill tries to rescue Matilda, chaos ensues when an officer mistakenly kills a doctor, inciting panic among the congregation. In the ensuing fray, Doris successfully manages to hide Matilda, allowing Jill and her children to flee into the woods.
They seek refuge in a garage, where Jill successfully manages to commandeer a car after cleverly eluding two men. As they navigate their way to The Hub, Noah finds a map that could guide them there. In a twist of fate, an escaped prisoner steals their new vehicle, inadvertently taking Matilda along with him. Encountering other escaped inmates who threaten them, they are unexpectedly saved by the man who initially stole their car, Dodge.
Together, Jill, Noah, and Dodge traverse plane wreckage, searching for supplies. Amid the chaos, Jill imparts critical survival skills to Matilda, teaching her how to drive in case the worst happens and she's left to fend for herself. Their journey towards The Hub is fraught with peril as they fend off dangerous individuals attempting to harm them.
Eventually, they arrive at The Hub, but Jill decides to send Dodge away with the car for his safety. Disguised as a lab worker, she infiltrates the facility in search of the other woman capable of sleep. There, she finds her in a dire state of health and learns that hope for a cure is bleak. Desperate for answers, she tries to convince this woman to protect Matilda, only to learn that the research being conducted involves using a drug that merely masks the symptoms of their condition, leaving horrific neurological damage in its wake.
Under mounting pressure, the army confronts Jill and her family, leading to Matilda tearfully confessing that she can still sleep. As the studies proceed, they uncover that the unique property allowing Matilda to sleep stems from a solar flare that had disrupted their brain functions. In a heart-wrenching twist, the experimentations lead to tragic outcomes, including the death of the woman who could sleep.
In a climactic confrontation, as soldiers descend into chaos, Jill and Matilda make a daring escape, but not without heartbreak. As they attempt to revive Noah, who is caught in a deadly hallucination, time is of the essence. In a shocking conclusion, it's discovered that the reason the children could sleep was that they both briefly experienced death, leading to a haunting reality as they drown Jill only to resuscitate her, awakening just as the camera frames her eye before cutting to credits.
