Ratsasan Tamil Full Movie Online HD, The story is Arun (Vishnu Vishal) an aspiring film director to take up the job of a Sub Inspector, after his father passes away. His uncle (Munishkanth Ramadoss) helps him get the police job. While Arun faces issues in adjusting to the lifestyle of a police officer, a series of mysterious murders happen in the city, that too of innocent school going girls. Vishnu Vishal comes into the scene and with the resources he has, he sets out to search for the killer. Why is the psycho killer targeting only school girls and whether Arun find the psychopath, forms the rest of the plot.