Balki's Paa stars the legendary Amitabh Bachchan who plays a 13 year old progeric child, the talented Abhishek Bachchan and the Brahmin beauty Vidya Balan. The film which releases on December 4th has Amitabh as Abhishek's 13-year-old son Auro who is suffering from a rare disease progeria that accelerates ageing. Vidya plays the mother to Amitabh and she mentions that it was a great experience for her.