The plot is discussed in detail, the way I saw it. So SPOILER ALERT ! But I guess most of you have already seen it.. *** It all starts with a crying baby in the arms of a woman in the packed Calcutta Metro. A police officer is looking around for a bag, or anything suspicious. Now who would suspect a woman with a baby? And that too the baby's milk bottle? The bottle breaks, a poisonous gas is realised and everyone exposed to it dies. Fast forward two years, here comes Vidya Bagchi, a heavily pregnant women to the dirty yet beautiful and thoroughly romanticised city of joy. The police officer, Rana, is more than happy to help her, carry her bags, etc. Now, I must admit that Calcuttans are helpful people, but police? I've never met one but in movies they are always portrayed as annoying people. But then again she is pregnant, and people are always willing to help her, aren't they? It seems like an intelligent point. But as the story progressing you come to believe it