More than Hindi cinema, I think, Bengali cinema has drawn from Western literature: including not just the more serious literary works, but also a good deal of popular literature. Of these, mysteries have been adapted often (possibly a reflection, too, of the fact that there’s been a long and much-respected corpus of Bengali mystery and detective fiction?) This is one, based on Arthur Conan Doyle’s The Hound of the Baskervilles.
The film begins with a brief and mysterious scene in which somebody finds a dead body among the marshes of a principality called Ratnagarh. We are never shown the face of the man who stumbles upon the corpse; but the news of this death is brought to Kolkata, to the ace detective Smarajit Sen (Shishir Batabyal) by Dr Palit (Kamal Mitra), the doctor at Ratnagarh. Sen’s assistant, Sanyal (?), is also present.