In 1930, a young Usha (Sara Ali Khan) watched her schoolteacher, an earnest man and supporter of Gandhi, get beaten up by the police. As a young child, barely 3 feet high, she still tried to stop the police and got hurt in the process. At home, her father, a judge named Hariprasad (Sachin Khedekar), locks her up in a room to try to curb her courage. The next day, they watch Siberian cranes from their window, and Usha exclaims that she wants to fly too. Hariprasad introduces Usha to the radio as a medium through which she can get news from the whole world.Many years later (in 1942, Bombay), a 22-year-old Usha is at the heart of the freedom fight, something her father, who is still compliant with the British and enjoys the benefits of the same (receiving a car for his work), doesn't know about. Usha has a few friends along with her, including a man named Fahad (Sparsh Srivastav) and the love of her life, Kaushik (Abhay Verma). Other colleagues include Antara (Aditi Sanwal), Bhaskar (Pratik Yadav) and Kamat (Sangram Salvi). The gang gets involved with the Congress party at the insistence of Balbir, their leader. Usha lies to her father and swears she has nothing to do with them.Usha and the gang get to see Gandhi (Uday Chandra) a little while later, and she pledges to become a "Brahmachari." This includes a vow of celibacy and makes Kaushik very upset. Though initially he's heartbroken that she would make such a decision without speaking with him, he ends up continuing to fight anyway. This is when Gandhi launched the Quit India Movement. The British consider this as an act of treason since the 2nd world war is still going on. The British ban the Congress Party, and in the process, all of the big names and the Congress party leaders got arrested. During this time, Usha and the gang attempt to keep the Indian Flag upright but get brutally beaten up by the police. Still, the gang doesn't plan on giving up soon, or at least Usha and Fahad. Seeing as all the press is controlled by the enemy, there's one thing lacking in the country and that is communication. As the British spread their lies, the country's unity is broken, so Usha comes up with the idea of starting an illegal radio broadcast. Immediately, two of the members of the gang (Antara and Bhaskar) decide to leave because they don't plan on getting hanged.Usha, Kaushik, and Fahad find themselves in a difficult position when the radio transmitter they want to purchase is going to cost them (Rs 4000, or the cost of 1 Kg of Gold) much more than they expected. Still, Usha is determined to get her hands on it. This is when her grand aunt (Madhu Raja) offers to sell some of her gold because this is the only way she can contribute to the Quit India Movement. Overjoyed, Usha and the gang get the engineer, Firdaus (Anand Tiwari), to set up the radio for them and teach them how to use it. 42.34 is the frequency, and the gang broadcast recorded messages from the Congress leaders every night at 8:30 p.m. The message spreads quickly in certain parts of the country, specifically between Mangalore and Ajmer, even getting attention from Ram Manohar Lohia (Emraan Hashmi), a political agitator on the radar of the British.On the other hand, Usha is struggling to communicate with her father, who seems to be more distant than ever before. Usha tells Hariprasad that she is doing late night classes with a professor, while she was working on her radio broadcasts. When he learns that she is lying (Hariprasad invites the professor to home) and running a radio station, he tries to stop her again, but this time she runs away, calling his love an obstacle to her flight. She's willing to give her life for the country, and her father can't do anything to stop her now. As an independent woman, Usha becomes more involved with the party and finally gets to meet Lohia, an inspirational figure. When he learns that it is she and her friends who are running the radio, he decides to work with them to make the Congress radio the voice of the country. Seeing as all the leaders are locked up and there's no other way to communicate, this would be the only way to get the country to act on the Quit India Movement. Lohia brings in his technical experts to increase the range and the sound quality of the broadcast.With the help of Lohia's radio expert, the team has the perfect system to deliver clear messages across the country. Suddenly, everyone is tuned in to 42.34 at 8:30 p.m. every night, making it a nuisance for the British. The British thought that they had crushed the Quit India Movement, but Congress Radio has reignited it. This could lead to countrywide protests and agitation, so the British started to search for the radio operators. John Lyre (Alexx O'Nell), the man who arrested Gandhi and the rest, is put on a mission to catch the radio operators. Corrigan (Benedict Garrett) is the Chief of Military Intelligence who informs John that the transmitter is in Bombay. Kamble (Manoj Diwakar) is a policeman working for John. He warns Balbir that the police are on the hunt for Congress Radio.Lyre realizes that there are only a few radio engineers in the city and manages to catch Firdaus, who gives up the position of their new transmitter (the only way they could've countered triangulation). Earlier, in the process of saving Firdaus, Balbir (Godaan Kumar), an ardent member of the fight, sacrifices himself.On the other hand, seeing Usha put herself in more danger (she was almost arrested by the police when she went to procure a transmitter range enhancer from a person, who turned out to be aligned with the police) as the days go by, Kaushik decides to leave her side because he can't watch her set herself up for inevitable death. Somehow, for a little while, the kids succeed in hiding the radio from Lyre, but soon, using American technology (including a radio signal detection van) and triangulation, Lyre is able to find the radio.Usha is stopped in her stride while trying to escape from the building where they're operating the radio. Somehow, Fahad and she are able to escape and hide the transmitter from the police, though their entire plan seems to be in jeopardy. They now know that John is using 2 radio detection vans and can pinpoint their location within 5 minutes. Usha suggests using 2 transmitters so that are not allowed to fixate on one location.Diwali is chosen as the day for revolution, and in pockets all across the country, people start to prepare for a revolution. On the other hand, Lohia's location is compromised, but he continues to work from the shadows, now leaving everything up to Usha and Fahad. Firdaus is arrested by John and the location of one of the transmitters is also compromised. Usha and Fahad will both give their lives for the country in the blink of an eye, but Usha manages to hurt Fahad's feelings by using his limp against him. Fahad gives her his blessings because he claims he'd have done the same thing.Usha knows there's no way she won't be caught this time, and she's okay with that as long as Lohia's complete message reaches the country. Kaushik shows up now, telling Usha that for some, revolution is their love, and for others, love is their revolution. The two of them block the doors to make sure the police can't get in easily because, as soon as the broadcast starts, there's only 5 minutes until they're found out. Lohia's message is quite a long one, and all Usha wants is for him to make the declaration.Ultimately, the police break in right after the declaration is made, and the revolution begins. Usha and Kaushik are caught as the national song Vande Mataram plays on the radio. Kaushik is unable to stand the torture and signs a paper naming Lohia as the instigator of the revolution. In the meantime, Usha does not budge.Usha was sentenced to four years of imprisonment. While in prison, she receives a letter of apology from her father. He's never felt more pride than as the father of Usha. He even gets a visit from Lohia and finally breaks away from the comfortable shackles of the British. When Usha is released from prison, 20,000 people come to receive her, despite it being illegal for so many to gather. Kaushik and Fahad are in the crowd too, and Usha's father claims that she's not just a revolutionary; she is herself the revolution. Lohia was caught in 1944 and continued to fight much later.