Sin Sister is a Bengali language Indian psychological thriller feature film, based on the novel Sin Sister, by Australian novelist Geri Hemer. The film is produced by Geri Hemer and Pinaki Ghosh under the production banner Power Publishers & Motion Pictures.
Identical twin sisters Piyu and Kuhu come to work under bestselling youth icon author Durjoy Mitra as his assistants. Durjoy and his fiancee Tanushree are getting ready for their imminent marriage, when something unexpected happens to Tanushree. Shrewd police detective Agnibesh Chatterjee swings into action and is determined to solve the puzzle that arises.