Agni Natchathiram
() is a 1988 Indian Tamil-language masala film that was written and directed by Mani Ratnam. The film stars Prabhu, Karthik, Amala and newcomer Nirosha, with Vijayakumar, Jayachitra, Sumithra, Tara, S. N. Lakshmi and G. Umapathy in supporting roles. Its story revolves around two half-brothers who come into conflict with each other due to their claims for legitimacy as sons of a common father. Ratnam intended  to follow Mouna Ragam (1986); he completed the script but chose to prioritise Nayakan. Although some scenes were filmed during a break from Nayakan, production on  stalled for nearly a year and resumed in late 1987 after Nayakans release. was produced by Ratnam's brother G. Venkateswaran; it was filmed by P. C. Sreeram, and edited by B. Lenin and V. T. Vijayan. was released on 15 April 1988, the week of the Tamil New Year festival Puthandu, and became a box-office success, running in theatres for over 200 days. The film won two Filmfare Awards South, three Tamil Nadu State Film Awards, and five Cinema Express Awards. It became a trendsetter in Tamil cinema, set a new standard in the use of lighting, and was remade in Hindi as Vansh (1992). Plot 
In Madras, half-brothers Gautham and Ashok are the sons of senior government Indian Administrative Service (IAS) official Vishwanath. Gautham's mother is Vishwanath's first wife Susheela, and Ashok's mother is Vishwanath's second wife Kamala. Both Gautham and Ashok inappropriately express their anger towards their father to others, and display open antipathy towards each other. Gautham, a trainee Indian Police Service (IPS) officer, meets the Commissioner's daughter Anjali and they slowly become lovers. After graduating from the police academy, Gautham is appointed Assistant Commissioner in Madras. Around the same time, Ashok meets a mysterious girl and they also form a romantic relationship. Meanwhile, Vishwanath is appointed head of an inquiry commission to investigate a nefarious factory owner called Chidambaram. One night, Ashok and his friends run into Gautham and Anjali; one of Ashok's friends teases Gautham, who arrests Ashok's friend on an invented charge. Enraged, Ashok and his gang throw stones at Gautham's house, accidentally injuring Susheela. The next day, Gautham arrests Ashok after provoking him into attacking him. Because Vishwanath is out of town, Susheela helps Kamala bail Ashok and offers snide, unsolicited advice about raising her children to be law-abiding. Meanwhile, Chidambaram repeatedly tries to bribe Vishwanath but is rebuffed and orders an assault on Vishwanath. On the day when Ashok's sister Mallika is meeting a prospective groom's family for a matchmaking ceremony, Vishwanath fails to arrive, causing the groom's family to question the seriousness of the marriage between Kamala and Vishwanath. Ashok is enraged; he goes to Vishwanath's house and berates him but realises his paternal grandmother has died; Gautham throws him out. Later, Ashok learns his girlfriend also comes from a broken family. The Commissioner learns of Gautham's romance with Anjali and, based on his father's behaviour, doubts his monogamy. Mallika runs into Gautham and Anjali on a commuter train; Gautham protects her from ruffians hired by Chidambaram to harass her, and he and Anjali accompany Mallika home safely. Mallika addresses Gautham as her elder brother but before he can respond, Ashok arrives and throws him out. Another altercation occurs at a wedding. The next day, they get into a huge brawl in public. Vishwanath berates them both, lamenting his public humiliation at his sons' behaviour. While Vishwanath is leaving his office, he is run over by a truck driven by one of Chidambaram's thugs and becomes comatose. Mutual fear brings the families closer as Susheela and Kamala wait by his bedside. Chidambaram arranges for Vishwanath's murder in the hospital. When the thugs attack, Gautham and Ashok foil the murder attempt by switching to the ambulance that Vishwanath was in. The next day, the brothers take the bandaged Vishwanath into the commission's office to submit evidence of Chidambaram's crimes. Chidambaram is arrested and the brothers high five each other. 