What is "pratidwandi"

Pratidwandi or Pratidandi (literally Adversary, Opponent or Competitor in Bengali; known internationally as The Adversary) is a 1970 Indian Bengali drama film directed by Satyajit Ray based on the novel by Sunil Gangopadhyay. It is the first part of the Calcutta trilogy. Set during the period of the Naxalite movement in Bengal, Pratidwandi tells the story of Siddharta, an educated middle-class man caught up in the turmoil of social unrest. Corruption and unemployment is rampant, and Siddhartha cannot align himself with either his revolutionary activist brother or his career-oriented sister.

The film also experimented with techniques such as photo-negative flashbacks and X-ray digressions.