In Los Angeles, Jill LaBeau, portrayed by Lola Kirke, serves as the dedicated friend and personal assistant to the glamorous movie star, Zoë Kravitz, who plays Heather Anderson. When Heather unexpectedly opts out of an upcoming film, it stirs frustrations and disappointment among those involved, as the project can't move forward without her. One night, at Heather’s insistence, Jill enters a diner to inform the director, Greg, played by Nelson Franklin, of this sudden change. Following this, Heather arrives, joins Jill, and eventually encounters an eager fan, Sierra, personified by Jessica Parker Kennedy, who requests a picture. Though initially reluctant, Heather agrees, and the photo winds up on social media, causing quite a stir.
As they exit the diner, they are bombarded by paparazzi, one of whom, Stan, played by James Ransone, probes Heather about her ex-boyfriend Devin, linked to Reeve Carney, and her rumored new flame, Tracy, acted by Greta Lee. Afterward, the two women retreat to Jill's apartment, where Heather requests Jill’s .22 snub nose revolver, citing safety concerns due to the burgeoning anger of upset parties. Jill, although hesitant, complies and loads the gun for her friend. They then head out to a nightclub where Heather shares a passionate kiss with Tracy, who tells her she will be at the cabin the following day.
Later, Jill and Heather return to Heather’s lavish mansion, where they decide to spend the night. Just before sleep, Heather notices a motion light flicker outside, but Jill dismisses it nonchalantly, suggesting it’s just a coyote. The next morning, an accidental discharge of the gun while Jill attempts to handle it leads to chaos, as she shatters a nearby coin case. In a moment of self-reflection, Jill admits to Heather that she considered taking the gun back but ultimately chooses to leave it with her. However, upon returning to the mansion after running errands, Jill is horrified to find Heather dead on the floor, the gun beside her, coupled with the absence of a coin collection.
The arrival of the police, led by Detective Edward Ahn, played by John Cho, only intensifies Jill's distress. Over tea, Ahn interviews her, but soon after, Jill feels compelled to contact Tracy, albeit only leaving a message upon reaching the beach. After a follow-up with Heather's agent, Jill returns home only to find police forces crowding her apartment building. In an effort to avoid detection, she is ultimately caught by Ahn, who pulls her aside for questioning. With all evidence suggesting her involvement—fingerprints on the murder weapon and gunpowder residue on her hands—she spots Stan recording their conversation. Seizing the opportunity, she discreetly slips away.
In a desperate bid for answers, Jill dyes her hair blonde and approaches Greg, who is packing for a trip to Scotland. Their conversation revolves around the mystery of Heather's murder but is abruptly interrupted by a knock from the police. As Jill evades capture, she decides to confront Devin, seeking information regarding his whereabouts on the night of the incident. During their conversation at a bar, Devin sidesteps her inquiries, shifting focus back to Heather’s relationship with Tracy. As he exits, leaving behind a hotel key, Jill is determined to uncover the truth. A search of Devin's hotel room leads her to discover a rare coin—a possible link to the theft from Heather’s home. Hiding in the closet, she overhears Devin instructing his girlfriend to provide an alibi, raising further suspicion.
Calling Tracy for assistance, Jill heads to her place, revealing the rare coin she'd found. However, Tracy dismisses its significance, declaring it could merely be one of Devin's treasures. That night, Jill overhears Tracy making suspicious phone calls, mentioning plans to "bring her up to the cabin before something happens". While exploring, she uncovers the very coins stolen from Heather's collection, prompting her to stealthily escape.
Managing to flee from pursuing police, Jill finds herself at a laundromat where she receives a message from Detective Ahn. A shocking news report emerges, retracting the identification of Heather as a murder victim. As Jill browses social media, she stumbles upon Sierra's profile, discovering their striking resemblance and a matching tattoo, deepening the conspiracy.
The following morning, Jill bravely rides her motorcycle to the cabin, only to find Heather alive and well. The realization strikes hard: the victim is actually Sierra, who had been shot while attempting to invade the house. Gripped by a mixture of fury and betrayal, Jill confronts Heather, who ultimately offers a raw apology for the chaos that ensued. The tension culminates in a moment of catharsis as Jill is permitted to punch Heather in the face, a symbol of the complicated dynamics of their friendship.
In the aftermath, Jill assists Heather in preparing for a television interview surrounding the scandal. Detective Ahn observes from a distance, and the future remains shrouded in questions of loyalty, truth, and survival amidst Hollywood’s dark underbelly.
