Vaishnavi is a very popular YouTube chef living in India. Her friend Ambujam's fiancé Cotton is stuck in a situation that demands him to go to London to work as a chef, but he is unqualified. He asks Vaishnavi to accompany him to pose as an assistant and help him secure the job so that he can be financially stable. Vaishnavi agrees and travels to London with Cotton and a relative Balki. They stay with their friends Ganesh and his wife Madhu and work as chefs a restaurant. Vaishnavi meets Sandeep there, and they fall in love. One day, on a boating trip in a river, Vaishnavi accidentally injures herself and washes off her blood in the water. This triggers the vengeful spirit of a dead woman at the bottom of the river. She possesses Vaishnavi, who goes on a killing spree. Her friends experience numerous paranormal occurrences soon after and consult with a priest to find that Vaishnavi is possessed. The spirit turns out to be Mohini, a lookalike of Vaishnavi. Meanwhile, Sandeep proposes to Vaishnavi, and they get engaged in the presence of his family. They meet Sandeep's mother Menaka and his estranged father Vicky/KVR. Mohini is enraged upon seeing him, and this reminds her of why she was killed. Mohini was an architect working for a construction company owned by KVR. She finds out about the child sacrifice rituals that KVR believes in and goes on to rescue children from a child trafficking gang. KVR and the gang are arrested, but they get released because of KVR's political influence. KVR and his men then capture Mohini, kill her, and throw her body into the river. Now that she has found a doppelgänger in Vaishnavi, Mohini is back for revenge. She goes after KVR and kills him, but not before telling that all of his generation will be killed by her, and that includes Sandeep. Menaka comes to know of this and tries to protect Sandeep from Mohini with the help of a Buddhist monk. She also contacts Mohini's mother, who agrees to help with the rituals that they are performing. The monk tells that in addition to the rituals, either Vaishnavi's body must be destroyed or a human sacrifice has to be done to appease Mohini. They all prevent Mohini from attacking Sandeep and try to save Vaishnavi from dying in the process. Mohini's mother finds that because of her daughter's vengeance, two innocent lives will be lost. She realizes that Mohini's spirit needs just one human life in order to be satisfied, so she kills herself and offers as a sacrifice to Mohini. Mohini's spirit is finally at peace and leaves Vaishnavi and Sandeep alone. Later on, it is shown that Mohini's spirit still lives on and hunts down anyone who tries to cause harm to children.
signed on to play the titular role in the film during early May 2016 and announced that she would collaborate with director Ramana Madhesh for the first time. Titled Mohini, the film was announced as a production venture for Prince Pictures, with Vivek-Mervin as music composers and Dinesh Ponraj as the editor.
Filming
The film began production in London during June 2016 with scenes shot in areas including Leicester Square, Piccadilly Circus and Tower Bridge. They held a month long schedule, with Hindi actor Jackky Bhagnani joining Trisha and a team of comedians for the schedule.
Tamil Nadu theatrical rights of the film were valued at 6 crore. The satellite rights of the film were sold to Zee Tamil.
Criticism
The moral of the film's story was questioned, since according to the plot human sacrifice was necessary, which took place during the final scenes. Other controversies include some negative portrayals of the London city and the mentioning about the British rule of India and the plunder of India by the British East India Company.
