Mersal is an action and thriller movie directed by Atlee and co-written by Atlee, K. V. Vijayendra Prasad and dialogues by S. Ramana Girivasan. The story revolves around two twin brothers in which one is a magician avenging for his father’s death and medical crimes. The other one is a reputed doctor who charges meagre amounts from his patients. Maaran, a sincere doctor who fights against corruption and Vettri a magician who is out for a revenge. Both of them are estranged brothers and once they come together, they get to know about their common enemy, Daniel, who had killed their father and mother.