ANGAD RAINA is a successful architect trapped in an unhappy marriage with KANIKA RAINA. After years of struggling and failing to make the marriage work, in a state of utter despair, he tries to murder his wife by smothering her with a pillow at their home, but fails. Kanika calls her sister MONIKA MISHRA for help who is a resident heart surgeon and had recently returned from the USA along with her 6 years old daughter KAIRA RAINA leaving behind her husband VISHAL BATRA for good. Monika arrives with Police who arrest Angad for attempted murder. Monika takes Kanika to her home, where she now lives with her daughter and her mother MADHOO MISHRA.
While staying with Kanika, Monika notices that Kanika is a compulsive liar as well as an alcoholic. Monika further discovers that she is suffering from some mental disorder for which she had been consulting DR. KAMATH, a reputed psychiatrist. Monika and Madhoo contact Dr. Kamath who then tells them that Kanika suffers from “Masochistic Personality Disorder” also known as “Self Defeating Personality Disorder”, where the patient has a compelling need to be sad, and in order to do so, they create (and sometimes imagine) situations that make them unhappy. Dr. Kamath also informs Kanika and Madhoo that this, most likely, is a result of repressed memories of some childhood trauma that Kanika had suffered, which have resurfaced as a result of a recent trauma. Madhoo informs Dr. Kamath that she lost her husband when Kanika was a teenager and her dire financial status compelled her to move to Kanpur with her daughters, where her brother took her in. Madhoo mentioned that Kanika could never completely get over the loss of her father and the move to Kanpur only further pushed her into depression. Monika and Madhoo believe that this trauma of her childhood may have resurfaced because a few years earlier Kanika met with an accident in the last month of her pregnancy because of which she lost her unborn baby, as well as the ability to conceive in future.
Monika is now confirmed that Kanika’s belief that Angad and Sonia are having an affair is ill founded, and decides to meet Angad, who is now out of jail on bail, to resolve issues so that Kanika and Angad can get together again. However, when Monika reaches Angad’s house, she finds him unconscious after having suffered a heart attack and rushes him to the hospital where she works.
Monika takes very good care of Angad at the hospital. Knowing that Kanika would not like her meeting Angad, she does not tell Kanika about it. While Monika is waiting for Angad to fully recover so that she could resolve the differences between Kanika and him, Angad, who is presently an emotional wreck, gets attracted towards Monika and despite trying hard to restrain himself falls hopelessly in love with Monika who is completely oblivious of Angad’s changing feelings towards her. After getting discharged from the hospital, Angad and Monika continue to be in touch. Monika also gets to know Sonia and her husband JOSEPH D’SOUZA through Angad, both of whom she becomes good friends with.
Meanwhile, proximity with Kaira encourages Kanika to give up on alcohol and recover from her state of constant depression. Finally Kanika decides to meet Dr. Kamath for treatment. Monika is very happy and shares this fact with Angad who gets greatly annoyed with Monika for bringing up Kanika in her conversations, who he says he can never come to forgive, and blurts out that he has fallen in love with her instead. Monika is completely taken aback by this admission, and in her anger and disgust decides to cut all ties with Angad. For six months she avoids all contacts with Angad who is desperate to meet Monika.
During this time Monika also comes face to face with her estranged husband, Vishal, who has returned to India. Vishal pleads to Monika to forgive him and let him meet Kaira but Monika is adamant to not allow this and warns Vishal to not try and get in touch with them. To ensure that Vishal does not come in contact with Kaira, Monika decides to enrol her in a boarding school in Nainital. Angad finally gets an opportunity to meet Monika without any fear and follows her to Nainital where he recounts to her his past with Kanika.
Kanika and Angad go to a party where Angad has a little too much to drink. On their way back home, they meet with an accident. Kanika, who was in the last month of her pregnancy, loses her child, and due to internal injuries is informed that she will not be able to conceive again. Kanika is distraught on hearing this news and blames Angad for this. She becomes increasingly insecure and suspects that Angad will leave her because of her inability to have children. Angad committedly supports Kanika during this time and tries his best to dispel her fears, but Kanika refuses to believe him. In her angst, Kanika steers into alcoholism. She becomes increasingly possessive of Angad and refuses to mingle with friends and family. Due to this, Angad’s relationship with his friends and parents suffer greatly. He finds respite at work where he could confide in Sonia.
One day at work, in order to comfort Angad, who was particularly upset that day, Sonia plants a friendly kiss on Angad’s forehead just when Kanika walks in to the office. Kanika is shocked to witness this and despite repeated explanations from both Angad and Sonia that there is nothing illicit going on between them, she refuses to believe them. She insults Sonia who walks out of the office in disgust.
The next day Kanika apologises to Angad and suggests that they go to Angad’s Office’s New Year party where she could apologise to Sonia. Angad is reluctant at first, but when Kanika insists, he agrees to go to the Party. At the party, Kanika apologises to Sonia but after having a few drinks, reverts to her earlier insecure self, accusing Sonia of having an affair with Angad and in the process slapping her in front of guests. Angad is extremely upset with Kanika’s behaviour and decides to move out of their home. While he is packing his things, Kanika threatens Angad that if he leaves her, she would commit suicide and the scene between Kanika, Sonia and Angad at the new year’s party that was witnessed by the entire crowd present, will ensure that Angad and Sonia are blamed for it. She further declares that she has already told her mother and sister about his affair with Sonia. Angad is disgusted by Kanika’s manipulative behaviour but finds himself helpless and is forced to stay back. At night, when Kanika is asleep, Angad in a state of complete despondency attempts to murder but fails.
Monika, on hearing the details of Angad’s life with Kanika, feels sorry for him but tries to convince him that Kanika’s behaviour was a result of her mental illness and alcoholism, and now that she has finally recovered from both, Angad must give their relationship another chance. Angad refuses to give in to Monika’s requests and tells her squarely that after what Kanika did, he will never go back to her. He again professes his love for Monika, who walks away from him.
Angad is unable to get over Monika and believes that the only way she would agree to marry him is if he divorces Kanika. To discuss this, Angad calls Kanika and asks her to meet him. Kanika, thinking Angad wants to patch things up, goes to meet him excitedly only to be shocked when Angad asks her for a divorce. While they are having this conversation, Monika meets Sonia and asks her to convince Angad to reconsider his decision regarding Kanika. Sonia tells her that Angad is quite certain about this and is in fact meeting Kanika at that very time to ask for a divorce. Monika starts calling Angad frantically to tell him to not discuss about divorce out of concern for Kanika. While Monika is calling Angad, her name and picture flashes on Angad’s phone which Kanika notices. Angad disconnects the phone and then switches it off. Kanika is shocked to see the picture and gets very disturbed to know that Monika and Angad have been meeting each other behind her back. This affects Kanika gravely who is now convinced that Angad and Monika are having an affair. Angad tries to explain that his feelings towards Monika are not reciprocated by her, but Kanika refuses to believe him. She comes home drunk and looks disgustingly at Monika which really disturbs her. She meets Angad the very next day and requests him to give Kanika one more chance and also informs her decision to hand over Kaira to Kanika and to leave for USA permanently. Angad flatly refuses to oblige and tells her that he would rather live alone than live a false life with Kanika.
Kanika, feeling threatened of losing Angad, calls Vishal and asks him to apologise to Monika and take her back so that Angad loses hope of getting Monika in his life. Later, Kaira informs Monika about Vishal’s coming home. Monika is shocked and confronts Kanika and her mother. Kanika and Madhoo try to convince Monika to focus on her own marriage and resolve her differences with Vishal. Monika, however, is quite adamant that she wants nothing to do with Vishal and her relationship with him is beyond repair. Kanika and Madhoo are unable to understand the reason behind Monika’s reluctance. Seeing that her own family members are not on her side, Monika finally breaks down and discloses that Vishal had sexually assaulted his own daughter, Kaira. Kanika and Madhoo are completely shocked by this revelation.
Kanika reaches Vishal’s home who is totally drunk. Kanika who is also drunk stabs him. Events of Kanika’s past flash in front of her eyes, where she finds herself in a room being sexually abused by her maternal uncle. Vishal succumbs to the injuries.
Kanika is imprisoned for 10 years. After her release she moves to the hill station where she works in an organisation which helps children who are victims of sexual abuse. On the insistence of Kanika, Monika marries Angad to give Kaira a secured childhood who has now grown up as confidant beautiful young girl who fortunately was not locked up in the prison of her past.