Paa is the story of Auro (Amitabh Bachchan), a 13-year-old boy with a rare genetic defect that accelerates ageing. Auro suffers from a progeria-like syndrome. While mentally he is a 13-year-old, but physically he looks five times older.

Inspite of his condition Auro is intelligent and witty and is always happy. Abhishek Bachchan plays the role of Amitabh's father in the film.

Abhishek's character in the film, Amol Arte is that a young, progressive and idealistic politician. Vidya Balan plays the role of Vidya, Auro's mother. Paa is about Auro and Amol's father-son-son-father relationship.

Trailer: Paa