30-something Mitali aka Meethi (Konkona Sen Sharma) suffers from Schizophrenia and is taken care of by her older, divorced sister Anjali aka Anu (Shabana Azmi), who is a professor, and their ageing mother (Waheeda Rehman). Although she was never married in real life, Meethi has created her own alternate reality in her mind in which she got married to her ex-fiancé Joydeep (Rahul Bose) and has five children. While Anu has dedicated her life to taking care of Meethi and her mother, even putting her own relationship with a fellow professor (Kanwaljeet Singh) on hold, in Meethi's imaginary world both the older women are holding her in the house and away from her husband and children against her will. She imagines her family to be living at the non-existent 15 Park Avenue in Kolkata.
After Meethi has a severe seizure, her case is taken up by a new doctor Kunal Barua (Dhritiman Chatterjee). While discussing her sister's case with the new doctor, Anu reveals that though Meethi had dormant schizophrenic traits since childhood, she led a very normal life till her early 20s, before a traumatic experience in the course of her job as a journalist made her withdraw from the outer world. Her fiancé, unable to deal with the emotional upheaval caused by the incidence, broke off the engagement. On the doctor's advice, Anu takes both women on a vacation to Bhutan, where they are spotted by Joydeep, now married with two children. In her present state, Meethi does not recognize Joydeep as the same man she is married to in her imagination, and befriends him. When Joydeep learns of Meethi's worsened condition and her imaginary world, he offers to help her locate the elusive family home - 15 Park Avenue.
Back in Kolkata, Joydeep drives her down to the part of the city where she believes her house and her family are. In a surrealistic climax, Meethi finally locates the house and finds her husband Jojo (as she fondly calls him) and her five children waiting for her return. She walks into the house, reunited with her 'real' family and is never seen again.
The film is the story of the relationship between a woman, Meethi, (Konkona Sen Sharma) who suffers from schizophrenia, and her sister Anjali (Shabana Azmi).
Meethi (short for Mitali) hails from an upper-middle-class family, fraught with a complex relationship structure. She is the child through the second marriage of her mother, and this is not explored in much detail in the movie since it focuses on other issues. Anu, her older sister, is a professor of physics at a university, who is shown to be intellectual and practical; however, the paradox in her character becomes obvious when she decides to forsake her personal life for her ailing younger sister. This shows her in a different light, and the viewer sees the contradiction throughout the movie.
Meethi is shown to have dormant schizophrenic traits since childhood, as depicted in the scene where Anu tells her doctor Kunal Barua (Dhritiman Chatterjee) that Meethi had always been a loner. Meethi felt everyone could hear her swallowing or gulping and so was embarrassed to go to school. Anu believes that a traumatic gang rape by political goons during Meethi's work assignment has pushed her over the edge and has led to the onset of full-blown schizophrenia.
Meethi lapses into incoherent delusions about a happy family and children which have been her erstwhile dreams. (In reality, her fiance Jojo (Rahul Bose) backed out from the relationship.) Clutching on to these straws, she desperately looks for her home 15 Park Avenue, where she feels she will be at peace. A chance meeting with her Jojo, 11 years after they broke up, gives Meethi a further impetus into her delusional world, as she touchingly trusts him to look for her home since now he is an outsider whom she does not recognise. For Meethi, the world is divided into her imaginary home and the outsiders, who keep her from going to her "family."
Guilt is a predominant colour in the landscape of this movie, depicted in the persona of every character, be it Anu, Joydeep or Mrs. Mathur (Waheeda Rehman). Iit is in the background of this tale of reality, illusion and the thin line between the two.Shabana Azmi as Anjali
Konkona Sen Sharma as Meethi
Soumitra Chatterjee as Meethi's father
Waheeda Rehman as Meethi's and Anjali's mother
Rahul Bose as Joydeep Roy
Dhritiman Chaterji as Dr. Kunal Barua
Kanwaljit Singh as Anjali's colleague and boyfriend
Shefali Shah as Lakshmi, Joydeep's wife