Patalghar is a 2003 Bengali science fiction film starring Soumitra Chatterjee, Biplab Chatterjee, and Kharaj Mukherjee. Aghor Sen, a scientist invents a machine which can generate waves and put any living being to sleep. When he is dead the instrument is also lost. 150 years later some goons and a Dr Bhoothnath sets out to search for it. But to reach Patalghar where the instrument lies hidden they must solve some riddles. Will they be able to reach Patalghar? Or will they need some help from an unknown source?