The title track landed first. Sach Ka Daayra, written by Gulzar, composed by Amit Trivedi and sung by B Praak, was unveiled Thursday at a packed Mumbai event for Daayra, the investigative thriller that opens in theatres on September 18. Three names from three different eras of Hindi film music on one song is a pairing worth noting on its own, but the room was there for the cast too.

Kareena Kapoor Khan led the conversation, and she went personal fast. Working with director Meghna Gulzar, she said, felt like a "full-circle moment," pointing to the decades-long association between Gulzar Saab and her mother-in-law Sharmila Tagore. Twenty-six years into her career, Kareena said, this film still made her approach a character like it was her first.

She had a word for what that felt like on set. She called Meghna a "taskmaster," and said the part demanded a kind of restraint she hasn't leaned on before, a far cry from the register audiences usually get from her. Kareena being Kareena, she also cracked that since the film forced her to keep her face still, she was making up the deficit in expressions right there at the launch. The room laughed.

Prithviraj Sukumaran took a more measured line. Daayra, from what he described, sits two opposing viewpoints against each other without picking a side for the audience. What made that workable, he said, was Meghna's own clarity about the story, which let both actors commit fully to their characters without editorialising through the performance. It's the kind of thing an actor says when a director has actually done the hard work of not flinching.

Gulzar closed the evening out with something closer to a lecture, and nobody minded. He spoke about how far filmmakers today are willing to go in picking subjects apart, compared to the cinema of his own generation. Truth, he said, behaves like a prism. Turn it and you get a different colour depending on where you're standing, which is more or less the argument Daayra itself seems to be making.

What's left unsaid, and what trade watchers will be tracking once the film is actually out, is whether that restraint Kareena talked about reads on screen as control or as distance. Meghna Gulzar's past work, built on procedure and quiet tension rather than melodrama, suggests she knows the difference. Daayra will have to prove it in front of an audience from September 18, the same week Bollywood's autumn slate starts getting genuinely crowded.