Bachchan, who starred in Sujoy's debut film 'Aladin', had lent his voice for a new version of the Tagore song 'Ekla chalo re' in 'Kahaani'.
"Tonight I go home. Tomorrow I reclaim my study from the kids. Then I try and write 2 scripts. one for THE Bachchan and one for the Balan," Ghosh posted on Twitter.
The 46-year-old filmmaker made his directorial debut with 'Jhankar Beats' and tasted success with his first thriller 'Kahaani'.