Plot
Royce Thomas and Reethu, a happily married couple, find their lives shattered after a devastating accident, which leaves Reethu an amnesiac. Eight years later, they both live at a hill station near Kottayam with their two children, Emma and Ryan. While Royce leaves to the hospital for work and the kids are sent to school, Reethu is taken care of by their maid, Rema. Reethu has an obsession for painting and her paintings are sold to an art gallery for a fair price. Royce collects her paintings and stores them in his resort in the outskirts of Kuttikkanam. She paints Bougainvillea flowers in all her paintings, leaving her further traumatized. Reethu admits that she hears growling noises from outside. Royce ensures her security check and convenes the technicians to install CCTV cameras around the house. Reethu panics on seeing the technicians approaching her in the kitchen and starts behaving violently until knocked down by Royce. Biju, Rema's husband, is skeptical of Reethu's behaviour.
In the meantime, Reethu gets to know of a missing case of one Chaya Karthikeyan, a student who was pursuing BBA in the Marian College, Kuttikkanam, the daughter of a Minister in Tamil Nadu. Reethu admits that she knew the girl she saw in the news channel. She hallucinates a girl chasing her among the sunflowers. She paints the sunflower garden and also paints a Batman logo and white rabbit for both Emma and Ryan. ACP David Koshy IPS, a police officer from Theni, investigates the missing case of Chaya and his prime suspect is Reethu, as her photo is revealed on the premises of the college hostel where Chaya stayed. As the interrogation begins, Reethu admits that she barely remembers Chaya's identity and cannot reminisce the past when David shows her photo on the premises. She later says that she saw Rema beside Chaya, leading to questioning Biju and Rema, who revealed that they were out of station for their relative's marriage. A confused David questions Royce, who reveals that Reethu has created her own world and lost her memory after the accident. To David's shock, Royce reveals that they have no kids and they were the hallucinations of Reethu. Biju decides to keep Rema distant from Reethu for her safety. Royce ensures them no harm from Reethu's side thereafter and brings Rema back to his house. After a while of thinking, Reethu confirms that it was herself beside Chaya, not Rema.
One night, Royce is attacked by a thief who broke into his house. He shoves the thief away and drives to the hospital with Reethu. It is revealed that Reethu had driven half the way as Royce lost his consciousness. Meanwhile, two more girls go missing. David hires Meera Yashodara, an expert criminologist to gouge out the truth from Reethu and unravel the mystery behind the missing cases; Meera approaches Reethu in a friendly manner. Reethu states that she remembers herself drowning while trying to recall the past. Losing patience, David interrogates rudely, leading to Reethu's tears. As Royce is questioned about her drowning, he assumes that she might have drowned somewhere in her childhood and that still haunts her. Reethu writes whatever happens around her in a piece of paper and tucks it under her bed, only to find them missing daily. David and Meera go to meet Manu Philip, the doctor who treated Reethu following her accident to enquire about her routines. Meera conducts a hearing therapy on Reethu as an attempt to get more evidence from her, but all in vain.
Meera goes to Royce's resort and explores the place to find the Bougainvillea flower around the place and finds the paintings of Reethu there. Shocked, Meera leaves. That night, Reethu visits her house with Biju and Rema and finds out that she too is missing. In a shocking twist, Meera is shown as being kidnapped and sedated by Royce in his resort, which is actually his ancestral house owned by his late grandfather, Devassy. Years ago, a young Royce had followed the evil path of Devassy who forcefully kidnapped girls and raped them before killing them. Back to the present, Reethu arrives at Royce's ancestral home along with Biju and Rema to inform Royce about Meera's disappearance. Royce locks up Reethu and Rema inside the house and kills Biju. Reethu, witnessing this, breaks the door and urges Rema to escape, only to be hit by Royce. Rema is taken to the room where Meera is kept sedated.
He takes Reethu to the room where her Bougainvillea paintings are kept and burns them, which helps Reethu recall her past. In a shocking revelation, Royce committed the kidnappings of the three girls along with Reethu, after which she was drowned by Royce to hinder her memory. He had stolen the paper chits which Reethu kept under the bed, in which, on one of them she wrote about Meera revealing to her that she had no children. Reethu tries to escape the house as dogs, raised as pets in the house, chase after her. Royce takes the shotgun of Devassy and follows her traces. Reethu falls in a deep pond and one of the dogs jumps into the water, scaring her. Royce shoots the dog and takes Reethu to the house and forces her to inject the sedative to herself. At this point, Meera musters up strength and strangles Royce with a chain, who throws the shotgun at Reethu who was running to inform the police. After Royce breaks the chain, he tries to convince Reethu that Meera is psychotic and is trying to harm them and their "kids". Reethu, who is convinced that she has no children, takes the shotgun and shoots Royce, after which he is smashed with a chair by Rema.
David arrives and finds the three of them at the farm house. They are taken into David's custody and reveal him Royce's true identity. Shocked, David says that Royce left no clues to suspect him and had a strong alibi as a doctor, convincing him that he always stood beside Reethu, protecting her as a husband. David also tells Reethu that her real name is Esther, and she was the only victim who was not killed by Royce. The accident from her past may have been her trying to escape from Royce's clutches when they committed the kidnappings. The next morning, David leaves after being called back to Theni. Reethu, now as Esther, goes to meet Royce, who is now in jail. Hence, the dark cases of the missing are unraveled.
