Adithattu denotes the 'lower strata in the society and the fishing community falls under this stratum. Adithattu will also explore the problems and livelihood of the fishermen community and will be a thriller subject.

A writer, whose writing is considered outdated due to the changing writing trends, leaves for Megamalai in search of solitude and wanting to write a new book. Upon arriving at Megamalai, a string of unfortunate events take place around him & his wife. Little does he know that it's not only his life that he's endangering.

Sivakumar is a timid young man, with a loving family in Madurai. His brother, a government official, earns the wrath of Simmakkal Ravi, the all-powerful gangster in the city. When he is murdered, Sivakumar and his father Kalayanasundaram plan to take revenge, in their own separate ways.