Mumbai, a city where the people are the lunchboxes.

Mumbai's Dabbawallahs are a community of 5000 dabba (lunchbox) deliverymen. It is a hereditary profession. Every morning the Dabbawallahs deliver hot meals from the kitchens of housewives to the offices of their husbands, and then return the empty lunchboxes back to the housewives in the afternoon. For 120 years they have provided the people of Mumbai with a taste of home in the office. They navigate through the overcrowded local trains, and chaotic streets. The Dabbawallahs are illiterate; they use a complex coding system of colors and symbols to deliver lunchboxes in the labyrinth that is Mumbai. Harvard University analyzed their delivery system, and concluded that just one in a million lunchboxes is ever delivered to the wrong address. 'The Lunchbox' is the story of that one lunchbox.

A wrongly delivered lunchbox connects a housewife – Ila, to Saajan Fernandes, a lonely man in the dusk of his life. Ila lives in Kandivili, the conservative middle class Hindu enclave. And Saajan lives in Ranwar village, Bandra, an old Christian neighborhood. Very soon Saajan will retire and bid goodbye to a Mumbai that crushed his dreams, took away his loved ones one by one, and turned his hair white. Just then Ila comes into his life. In the big city, that crushes dreams and recycles them everyday, both find a dream to hold on to. They exchange notes in the lunchbox and create a fantasy life. As the lunchbox goes back and forth, this fantasy becomes so elaborate that it threatens to overwhelm their reality.

In the end, they come to a crossroads where they must choose between the two Worlds. The Lunchbox is the story of loneliness, regret, nostalgia, and above all, of the mistakes that can also be miracles.