Royce Thomas, Kunchacko Boban, and Reethu, Jyothirmayi, are a happily married couple whose life is torn apart when a terrible accident leaves Reethu with amnesia. Eight years later, they carve out a life at a quiet hill station near Kottayam, where their two children, Emma and Ryan, brighten their days. Reethu’s quiet world, however, is colored by an intense fixation: painting. Bougainvillea flowers bloom in every stroke, a motif that seems to anchor her fragmenting memories. Royce, ever practical, pretends to curate these canvases for an art gallery, but in truth he stores them away at their farmhouse, a quiet facade masking something darker.
Chaya Karthikeyan, Athira Patel, a student, goes missing, and ACP David Koshy, Fahadh Faasil, bears the weight of the investigation as Reethu becomes the lead suspect because she was found on the college hostel premises just before Chaya vanished. In the interrogation, Reethu insists she does not remember being there, her memory a fog she cannot lift. Yet she recalls seeing Rema beside Chaya, prompting further questions about who else might have been present. David questions Rema and her husband Biju, who explain they were out of town for a relative’s wedding. The truth feels slippery, and Royce, in a chilling reveal, confides that Reethu has built a separate, self-created world—one in which they have no children—and that what the couple shares might all be a hallucinatory fabrication of her mind. To protect Reethu from harm, Biju decides to keep Rema away, while Royce promises there will be no trouble and brings Rema back into the fold. Yet, after a moment of introspection, Reethu remembers something unsettling: it wasn’t Rema beside Chaya, but herself.
As the investigation deepens, two more girls go missing. David enlists Meera Yashodara, a criminologist, to pierce through Reethu’s fractured memories and uncover the truth behind the vanishings. Meera begins a careful process of questioning, and Reethu speaks of drowning as a memory tries to surface, a drowning that may be connected to her childhood. She clandestinely tucks away scraps of writing under her bed, but those notes vanish one by one, almost as if someone is erasing her attempts to recall. David and Meera travel to speak with Dr. Manu Philip, the doctor who treated Reethu after the accident, Jinu Joseph in the role, hoping to uncover the medical threads of her memory. Meera’s hearing therapy yields little tangible evidence, and the investigation stalls.
One night, Reethu—and with her, Biju and Rema—go to Meera’s house only to discover that Meera herself has gone missing. The case takes a darker turn when Royce’s past surfaces in a brutal revelation: his ancestral home, a place tied to Devassy, reveals a long history of kidnapping and killing girls. Devassy, Nisthar Ahamed, Royce’s grandfather, had set a precedent that shadows Royce’s present actions. This shared history helps explain the terrifying pattern that has unfolded around Reethu and the others.
Back in the present, Reethu reaches Royce’s ancestral home with Biju and Rema to warn him about Meera’s disappearance. Royce traps them inside, kills Biju, and forces Reethu to watch as Rema escapes. He then drags Reethu to the room where her Bougainvillea paintings are kept and burns them, a brutal act that jolts Reethu’s memory awake. A grim, devastating truth emerges: Royce has been the mastermind behind the disappearances, and he and Reethu had been players in a grim cycle of kidnappings; Reethu was drowned by Royce to erase her memory. He has even stolen the paper chits Reethu kept under the bed, including one where she wrote about Meera’s revelation that she had no children.
When the house dogs—raised as Royce’s pets—close in, Reethu tries to flee. Royce seizes Devassy’s shotgun and pursues, but Reethu falls into a deep pond. A dog leaps after her, and Royce shoots the animal before dragging Reethu back to the house, forcing her to inject sedatives into herself. Meera, however, fights back with every ounce of strength and manages to strangle Royce using a chain, even as he breaks free of it and attempts to persuade Reethu that Meera is psychotic and a threat to their supposed “kids.” Desperate and convinced she has no children, Reethu pulls the shotgun and shoots Royce, who is then smashed by Rema with a chair in a bid for vengeance.
David arrives at the farmhouse and confronts the truth: Royce’s true identity had remained hidden behind a calm, clinical exterior, supported by a strong alibi. He reveals that Reethu’s real name is Esther, and she was the sole survivor among Royce’s victims, with the accident perhaps a failed attempt to escape his grip. The dawn breaks on a grim, solved mystery as the dark cases of the missing are finally unraveled.
In the aftermath, David departs, leaving Reethu—now understood to be Esther—paired with the weight of what she has endured. Esther makes a quiet way to meet Royce, who sits behind bars, a reminder of the maze of memory, manipulation, and danger that defined their lives. The film closes on a chilling note: the truth, once buried in Bougainvillea-painted memories, has finally come to light.
