A working prisoner is getting beaten up by a convict named Govind Raj. The prisoner beaten up gets saved by another prisoner named Sachidanandan. Later he is called to the station and he comes to know that he will be released from prison very soon. He also receives a letter from his brother saying that a surprise awaits him as he gets released. As he goes through the letter, old memories flash back in his mind. Sachi's father was about to remarry. Sachi was very excited for getting a new mother. He also saw that the mother had a son which was going to be his step-brother named Vishnu. He tries to befriend and love Vishnu but he rejects him but later on starts accepting him. His step-mother is also going to have a new baby. Once after returning from a function Sachi, witnesses his step mother harassed by her ex-husband and tries to take away Vishnu. Sachi kills the man while saving his brother and mother. He goes to a juvenile home for his crime and over there he befriends Khan, Ghani and Pareekkar. Once he witnesses Khan and Ghani getting beaten up by a sadistic police officer. Sachi kills the officer while trying to save his friends and hence goes to a central jail because he was an adult aged 16. He is sentenced for two life term sentences. In the prison, he discovers his ability to see in the dark. As he exits the prison he is well-received by his younger brother who was born after he went to jail who was Manu. He was also received by his prison friends Pareekkar, Khan and Ghani. They invite Sachi to join them to work with Edwin Moses who is a drug mafia leader. Sachi warns them and decides to lead a peaceful life with his family. The surprise awaiting him was that his brother Dr.Vishnu was soon to marry Vandhana who was a doctor and the marriage was postponed so that Sachi can witness the marriage as Vishnu was adamant. The marriage takes place and as Vandhana seeks Sachi's blessings, she realizes that he was the one who saved her from a gang and in the process of saving her, Sachi's back was scratched by a sickle. The next day Vandhana forces Sachi to tell the truth about him. When the police found out that Sachi could see in the dark, he and many other prisoners was sent for commando operations. They were often sent unarmed to face armed opponents. Sachi's jail term was extended as every time he went for the operation, the report written was that he jumped or escaped from the jail. Many prisoners never returned. Their bodies were found in random places. A police officer named Vedantham IPS approaches Sachi. He explains to him that the drug mafia has returned stronger as ever, and it is controlled by a person whom no one has seen named Edwin Moses. He tells Sachi that innocent people are used for drug business without their knowledge. Sachi rejects it saying that he wants to live peacefully with his family. Sachi and his family faces many troubles from Edwin Moses and Shetty. Later Shetty explains to Sachi that Edwin is doing all this for a drug container worth crores which is in Shetty's control. Sachi finds his friends with alliance with Edwin Moses but reveals to him that they had nothing to do with it unless a gangster named Muthan died. Edwin had been pestering them for the container. It was revealed that Sachi had the container. He had stolen it from Muthan earlier. Edwin's men attack Sachi and his friends. Sachi fights and defeats them when Vedantham arrives and kills Khan and Pareekkar, while Ghani survives. Sachi calls Vedantham from Pareekkar's phone and it is revealed that Vedantham was none other than Edwin Moses. Enraged by this, Sachi kills Edwin Moses. In the credits, Sachi repairs the old car as he reunites with his family.
In May 2018, Siddique revealed in an interview to The New Indian Express that his next Malayalam film is with Mohanlal and it will be released in April 2019. Later, media outlets reported that the film has been titled Big Brother. Soon, Siddique revealed that it is a big budget film with action and humour, and it would begin production in November that year. Denying the reports of Nayanthara and Innocent being cast in the film, he said "we are yet to confirm the cast as I have only a basic thread in my mind and am yet to start scripting". Big Brother was officially announced by Mohanlal through his social media on 9 October 2018 by sharing a title poster. It was said to be jointly produced by Siddique's and Jenso Jose's S Talkies, Philipose K. Joseph's and Manu Maliackal's Shaman International, and Vaishak Rajan's Vaishaka Cynyma. Big Brother was initially planned with a budget of ₹28 crore, but it went up to ₹32 crore while in production and the corporate company Carnival Movie Network joined the project to invest the additional money. S Talkies and Carnival Movie Network also distributes the film. A pooja ceremony for the film was held on 24 April 2019, followed by a recording session by music director Deepak Dev. Siddique was completing the final draft of screenplay in May 2019.
Casting
More cast were revealed in May 2019, including Arbaaz Khan, Anoop Menon, Vishnu Unnikrishnan, Sarjano Khalid, Chemban Vinod Jose, Siddique, Janardanan, and Tini Tom in pivotal roles. Big Brother marks the Malayalam film debut of Bollywood actor Khan. He plays Vedandam IPS, an encounter specialist. Mohanlal plays Sachithanandan, and Menon and Khalid portrays his younger brothers. Menon plays doctor Vishnu, according to him, Vishnu is the "nicest character" he has played so far. Regina Cassandra and Satna Titus were in talks to play the female lead roles that month. The former for the role of Arya Shetty, the daughter of a wealthy businessman and Sachithanandan's romantic interest, and the latter as the pair of Khalid's character. Titus was confirmed in that month along with another debutante Shilpa Ajayan as the pair of Menon's character. Cassandra opted out from the film due to scheduling conflicts. She was replaced by newcomer Mirnaa Menon, whose casting took place only few days before filming. Gaadha plays one of the three female lead roles in the film, it is her first Malayalam appearance and second film after Nimir.
Filming
began on 11 July 2019 in Ernakulam. Filming was initially scheduled to begin on 20 June 2019 with Mohanlal joining on 1 July after finishing his work in . The film was mostly shot at Bangalore with a few scenes at Kochi. Mohanlal was filming scenes in Kochi in September. In October, filming took place near the HMT factory in Bangalore. The team were also shooting in Mysore in that month. Lalitha Mahal palace was a filming location. The film was to be shot at the streets of Mysore but heavy downpour caused delay and filming was restricted to indoor sequences. Final schedule of filming resumed in mid-November. Final schedule took place in places such as Ernakulam and Coimbatore. Mirnaa had 100 days shoot. Filming was completed in December 2019, taking longer than expected. The budget also hiked to ₹32 crore. The stunts were choreographed by Supreme Sundar and Stunt Silva, and the songs were choreographed by Brinda, Dinesh Kumar, and Prasanna Sujit.
Soundtrack
The film features a background score and three original songs composed by Deepak Dev, with lyrics by Rafeeq Ahamed and Santhosh Varma. The audio launch function of the film was held at Darbar Hall Ground, Ernakulam on 26 December 2019. The soundtrack album was released by the label Millennium Audios on 21 December 2019.
Release
Big Brother was released worldwide on 16 January 2020. The satellite rights of Big Brother was bought by Surya TV and online streaming rights were purchased by Amazon's Prime Video.
