Diane de Monx is a driven executive tasked with negotiating a pivotal deal to acquire the rights from a Japanese anime studio, which is gearing up to produce cutting-edge three-dimensional hentai, for the French firm Volf Corporation. In her relentless pursuit, Diane makes a drastic decision to eliminate her superior, Karen, effectively taking charge of her portfolio. Accompanying her in this venture are her business partner, Hervé, and her assistant, Elise. However, Elise despises Diane deeply and seizes every chance to undermine her efforts.
Their journey takes them to Tokyo, where Diane and Hervé share a flirtatious dynamic while finalizing the crucial deal. With the rights secured, Volf Corporation seeks to collaborate with an American Internet company named Demonlover, represented by Elaine Si Gibril. Unbeknownst to her colleagues, Diane has been secretly reporting to Mangatronics, Demonlover's chief competitor, meeting with a shadowy handler to relay vital information.
As tensions rise, Diane uncovers that Elaine's company hides a dark secret: it serves as a facade for the Hellfire Club, a sinister site on the dark web that streams live acts of extreme sadomasochism. When faced with these shocking revelations, Demonlover dismisses any association with the Hellfire Club, even as its nefarious operations loom large.
Under pressure to finalize the deal for Mangatronics, Diane is instructed to infiltrate Elaine's hotel room and steal sensitive data. When Diane is caught in the act, a brutal confrontation ensues. In a fit of desperation, she uses a shard of glass to fatally wound Elaine and, in an act of chilling resolve, suffocates her with a pillow in a nearby storage closet. Just before succumbing, Elaine manages to strike Diane, leaving her dazed. When Diane regains consciousness, she finds no trace of the chaos—everything appears untouched.
Receiving a stern warning from Elise during a stormy drive, Diane is compelled to drop her off on a desolate street. Alone at the Volf offices, she accesses the Hellfire Club’s website, revealing harrowing footage of women subjected to appalling violence. In a return to her workplace, Karen ominously informs Diane that Demonlover is indeed linked to the Hellfire Club, leaving a camcorder tape that unveils Elise's complicity in covering up Elaine's murder.
Realizing she has become embroiled in a web of deceit, Diane learns that Elise is a spy for Demonlover, working covertly with Hervé. Exploiting Diane's dark secret to harness control over her, Elise coerces Diane into joining the Hellfire Club, escorting her to a remote mansion where Diane is drugged. Flashbacks unveil the harrowing truth: Diane had previously murdered Hervé while he attempted to assault her for a second time.
Subsequently transported to a desolate location, Diane regains consciousness in a dim, dungeon-like environment, clad in a vinyl outfit, with unsettling images of Diana Rigg as Mrs. Peel from The Avengers surrounding her. Attempting to escape, she almost succeeds but ultimately meets failure in a car crash during her flight.
In a chilling cross-section of fate, a teenage boy in the United States accesses the Hellfire Club using his father's credit card. As he crafts a sinister fantasy involving Diane, who is bound in a bondage suit, her silent gaze toward the camera captures the haunting reality of her situation while the boy dismissively continues his science homework.
