He was also trained by Nitya's father. During treatment he was able to maintain his composure of sanity under medication and was admitted there after the 4 murders he committed. It is revealed to the audience that it was not Nitya who murdered her family but Vinayan in his spree after Nithya's father was killed by his brothers and to further stop their attempt at harming Nithya. Both of them were actually promised to each other by Varma before his tragic death, and the voice over states that they are both very close to each other and will do anything to keep the other safe. The film ends with the real Dr. Nair swearing that he will catch Vinayan wherever he is hiding and it is shown that Vinayan and Nitya are happily living together in a beautiful house on the hills at peace. Finally free from the external world. Title of the film was announced on 17 February 2019 alongside the first official poster. "Athiran" marks the directorial debut of Vivek. According to Vivek, the story was formed based on a real-life account combined with inspiration from a short story written by Edgar Allan Poe. He said: "the story idea came up after I went to a Kalari school in Thrippunithura, Kerala, where autistic students were performing with the same prowess as the school's other students". The screenplay was written by P. F. Mathews. When Vivek briefed the story idea to Faasil two-and-a-half years ago, it was Faasil who introduced him Mathews. Vivek himself titled the film. Vivek cites "Ulladakkam", "Sesham", and "Devadoothan" as the major inspirations for the film, and were also inspired by "Shutter Island", "A Cure for Wellness", and "Stonehearst Asylum". Principal photography began in November 2018. The film was extensively shot in Ooty, Tamil Nadu. Filming was completed on 21 January 2019. It took 55 days to complete the filming process. The film is set in a psychiatric facility. The film score was composed by Ghibran, the film marks his Malayalam cinema debut. The film features three songs composed by debutant P. S. Jayhari, who was supposed to debut with the same director's shelved film "Aanenkilum Allenkilum". The lyrics were written by Vinayak Sasikumar and Engandiyoor Chandrasekharan.