The reason for this is because Sujoy Ghosh had a solid story in hand, and a great actor in Vidya Balan.

All of this is there in Kahaani 2, as well. The events in this sequel start much after the first film. Durga Rani Singh (we assume that is Vidya’s real name but you never know) has a child now and the trailer begins with her being involved in a hit and run case. She slips into a coma, and a police officer (Arjun Rampal) tracks her case using her diary entries.

Through the entries, he learns about her daughter, about that fact that she was embroiled in a kidnapping and murder case and was trying to escape to London.

The trailer opens with Vidya’s character receiving a phone call, wherein she is informed that her child Mimmi has been abducted. Next thing you see, she meets with an accident and goes into a coma. Just when you empathise with her sorry state, you’re told that she is Durga Rani Singh, a woman who is accused of kidnapping and murdering children. And that sets the spine-chilling story into motion.
While Vidya is back to impress you with her acting chops, Arjun Rampal as the investigating cop too seems promising. But from the trailer, one can safely say that the true hero of the film will be its story. So get ready for a thrilling ride as ‘Kahaani 2’ hits theatres on December 2, 2016.

Kahaani 2 - Durga Rani Singh | Official Trailer | Vidya Balan | Arjun Rampal