Kahaani is a suspenseful thriller directed by Sujoy Ghosh and released in 2012. The movie stars Vidya Balan as Vidya Bagchi, Nawazuddin Siddiqui as the intelligence officer Satyoki "Rana" Sinha, and Parambrata Chatterjee as the inspector S. Khan.
The film takes place in Kolkata, during the events leading up to the Durga Puja festival. Vidya Bagchi arrives in Kolkata from London, looking for her missing husband, Arnab Bagchi. She has very little information about her husband's whereabouts, except that he used to work for the National Data Center (NDC) and the company that hired him, MacNeil and Munshi (M&M), denies ever having heard of him.
Vidya begins her investigation by going to the police station, where she meets S. Khan, a kind-hearted but inexperienced inspector who takes her case. Khan offers to help Vidya find her husband, but when they start digging, they discover that Arnab Bagchi has no records, no passport, and no identity.
As the investigation proceeds, Vidya discovers that her husband might have been involved in a terrorist attack that took place in Kolkata a few years ago, and that he could be a key witness in an ongoing investigation. Meanwhile, Rana is sent to investigate Vidya's background, suspecting her of having a hidden agenda.
The film is full of twists and turns, and the suspense gradually builds up towards a shocking climax. Kahaani is known for its well-written plot, strong characterisation, and brilliant performances by the lead actors. The movie was critically acclaimed and commercially successful, leading to a sequel, Kahaani 2: Durga Rani Singh, released in 2016.
