The metaphor of the (mushroom) is central. Mushrooms grow in darkness, on rotting organic matter, and they appear overnight. The film uses this imagery to comment on:
“Kolkata is a city that grows like a fungus. It has no master plan. Each building, each relationship, each betrayal is a spore floating in the air, landing wherever it can. ‘Chatrak’ is that spore’s journey.” Chatrak 2011 Bengali Movie Wiki
While Chatrak has no conventional “songs” (a rarity for Bengali cinema), its soundscape is its true score. Music directors and Benedict Taylor (known for Ship of Theseus ) created an avant-garde mix of: The metaphor of the (mushroom) is central
Rahul’s attempt to reconcile with his girlfriend (Paoli Dam) while navigating the professional pressures of a massive construction project. on rotting organic matter