In January 2000, a tragic event unfolds in a Staten Island school when a boy named Cullen Active enters a classroom and opens fire, targeting his teacher first. Amid the chaos, Celeste Montgomery, portrayed by Natalie Portman, steps forward to calmly engage with Cullen, offering to pray with him. Unfortunately, he shoots her in the neck before continuing his rampage on other students.
As Celeste fights to recover from her grievous injury, she and her older sister Ellie (Stacy Martin) find solace in music, collaborating on songs that express their emotions. During a memorial for the shooting victims, Celeste performs a heartfelt piece called "Wrapped Up," co-written with Ellie, which unexpectedly catapults her into the spotlight. She quickly attracts the attention of a manager, played by Jude Law, who helps steer her career.
Over the next two years, Celeste navigates the overwhelming pressures that accompany her rise to fame while grappling with the shadows of her past. She and Ellie enjoy a close bond, spending time together and celebrating their success. However, their joy leads to reckless behavior, including one-night stands and a betrayal when Ellie has an encounter with the manager right before the September 11 attacks. This incident marks a turning point, creating a rift between the sisters.
Celeste's star continues to rise, with her music gaining traction on the radio and quickly warranting a demand for her debut music video, "Hologram (Smoke and Mirrors)."
Fast forward to 2017, the world faces a new crisis as a terrorist shooting on a Croatian beach raises concerns about a connection to Celeste's music, specifically due to the masks worn by the attackers resembling those from her video. Now 31, Celeste prepares for the opening night of her concert tour for her sixth album, Vox Lux. Her manager brings her up to speed on the pressing situation before she embarks on a series of interviews.
Before her first press engagement, Celeste takes her teenage daughter Albertine (the result of her earlier one-night stand) out for lunch, where her erratic behavior fuels chaos, leading them to be thrown out by the manager. It is revealed that six years prior, Celeste had tragically blinded herself in her left eye due to substance abuse.
Tensions rise when Celeste has a confrontation with Ellie after discovering that Albertine has recently lost her virginity, a situation compounded by Ellie being the primary caregiver since birth. As the interviews unfold, Celeste spirals into a precarious state, particularly when one interviewer broaches the subject of her past driving incident. Her publicist decides to call off the remaining interviews, urging Celeste to take a breather before the concert. Ignoring this advice, Celeste engages in drug-use and a heated moment with her manager instead.
That evening, as she approaches the concert venue with her entourage, Celeste grapples with a mental breakdown. Thankfully, Ellie steps in to support her before she takes the stage.
As the concert commences, Celeste dazzles with an array of performances alongside her band and dancers. The film concludes with a reflective note: after everything she has endured, Celeste revealed to Ellie that she made a deal with the devil to survive the shooting. The final scene captures her manager, Albertine, and Ellie watching her performance with deep contemplation, culminating in a powerful moment of juxtaposed fame and inner turmoil.
