Vijay Antony is an IT employee and he starts a happy life after his marriage with Arundathi Nair. Just as their lives sail in a smooth boat, our hero happens to hear a voice in his mind that tempts him to commit suicide. Inspired by this voice, he tries to oblige its command many times but is saved by his friends. Once, when he drives a car being accompanied by his friend Murugadoss, he hears the same voice and in turn ends up in an accident which leads to his friend's death despite the hero escaping unhurt.
After this incident, Vijay Antony shares his problem with his senior Y. G. Mahendran, who takes him to psychologist Kittu. During his examination, Kittu finds out that the protagonist was a teacher in his previous birth and was married to Jayalakshmi. Furthermore, he comes to know that after deceiving and killing our hero, the same Jayalakshmi is keen on getting him killed once again.
Knowing that Jayalakshmi is in Tanjore, the hero goes there in search of her. He finally gets a photo of her and is shocked to see that her face resembles his present wife Arundathi Nair. The rest of the movie then travels in a thriller path to find out the reasons for Vijay Antony's unnatural behavior and the hidden truth.
The whole story revolves around the hero, Vijay Antony, and having done justice to his character, he once again excels in the emotional scenes. The actor proves his skills by showing clear variations in both of his characters, but needs to improve himself in the romantic scenes.
Arundathi Nair looks beautiful and makes a perfect portrayal of a newly-wed wife with the romantic dialogues. The other artists Kittu, Y. G. Mahendran and Murugadoss have done their portions in an appreciable manner.
Newbie director Pradeep Krishnamoorthy has tried a different knot in his first attempt itself. After creating the needed thrill among the viewers in the first half, the answer to all the questions get revealed in the latter part of the film. Although the results seem to give the audience a been there, seen that feeling, it is the director's efficiency that makes the audience accept the consequences.
Vijay Antony's background scores play a big boon in Saithan. This was earlier experienced in the teaser of the film and the actor is able to maintain this tempo throughout the film. The name Jayalakshmi, being scored and pronounced in an unique pattern receives a special mention. Pradeep Kalipurayath's cinematography is excellent and does the magic in each and every frame. The effects look good and apt in unfolding a complicated screenplay.
In short, Saithan terrifies us with a smile.