Interestingly, the story came to Mehta through internet.
"It's a story that was mailed to me by a girl called Ishani Banerji. It just blew my mind. I have to tell this story because marginalized people in our society always interest me," confesses the director, whose next release "Citylights" is about a migrant couple's self-effacing anonymity in Mumbai.
"We've stopped seeing these nameless migrants in the cities. Their lives never concerned us. Now they've become invisible," said Mehta, who has again cast Rajkummar Rao in the lead.
Mehta describes "Citylights" as a sequel to his year 2000 satire on migration - "Dil Pe Mat La Yaar". To portray abject poverty and ground-level austerity, Rajkummar and his leading lady Patralekha had to shoot under the harshest of circumstances.
"My producers Mahesh and Mukesh Bhatt were willing to provide all the comforts required for shooting. However, I deliberately made them shoot under gruelling conditions. No make-up van and no luxuries were allowed."
The director describes his partnership with the very talented Rajkummar as "unbreakable".
However, his next film about a gay hero won't star Rajkummar, but Nawazuddin Siddiqui.
"I need an older actor to play the gay character. The story takes the character through a very wide chronological arc. Nawaz is more suited to the character. But I am writing a very big biographical story for Rajkummar, which would be set in the Hindi film industry during the 1950s. That's the film Rajkummar and I are doing next," he added.
Marginal heroes would continue to haunt Mehta's cinema. In real life too, the filmmaker is haunted by communal forces taking over the country.