Isai begins with a voice-over that tells us the film will show us what jealousy can do to a genius. And it dives straight into the plot. AK Shiva is the new hotshot film composer in town and the man he has dethroned, Vetrichelvan, who was ruling the scene for 30 years, is enraged by his success. He is the Mozart to Vetrichelvan's Salieri. Earlier in the film, we get a scene that is similar to the one in Pudhu Pudhu Arthangal — Vetrichelvan is signing autographs but when Shiva turns up, the fans rush to him leaving him all alone. The man is so consumed by rage that he goes and murders the director who gave Shiva his big break! And because of this rage, he is unable to play music and so decides to ruin his rival's life and career. For this, he hatches a plot to mess up with Shiva's mind and drive him insane.

SJ Suryah is one director who goes to any extent to keep his audience entertained. And, in Isai, he opens up his bag of tricks after a gap of 10 years and shows that he has still got his groove. There is an exaggerated quality to the performances, shot compositions and the score (he makes his debut as a composer here) in Suryah's films, but they should be seen more as a stylistic choice. Isai isn't as taut a thriller as Vaali but despite being overlong (lengthy scenes with too much dialogue), it is fairly engaging. The film doesn't truly come together as a whole but the scenes have the stamp of a director with a sure hand.

Shiva is shown as a musician who is fascinated by everyday sounds and finds music in them (he even goes to a forest to record the sounds of nature for an album) and so, we willingly buy into most of Vetrichelvan's plan to upset his universe. As Jim Carrey in The Truman Show, Shiva doesn't realize that everyone around his acting a specified role and starts doubting if he has genuinely gone mad. Sathyaraj hams it up quite a bit in the beginning but as the movie progresses and becomes a little chaotic, it is his casual villainy that keeps us entertained. The scenes between him and Ganja Karuppu, who as his servant, gets into a Catch 22 situation every time he opens his mouth, are quite amusing.

The erotic tones in the romantic scenes once again underline the fact that, for him, love will always be inseparable from lust. Interestingly, for a director who doesn't let go of an opportunity to show his heroine's skin (maybe, he wants to pander to his fan base and keep them satisfied), Suryah's heroines generally have a huge part to play in his films and that is the case here as well. Jennifer, the girl he falls in love with and marries, is quite an interesting role but Savithri, despite the better lip sync, seems too fragile an actress for this complex character.

But, there are times when the film turns frustrating as scenes go on and on, in convoluted fashion, with no end in sight. And with the climactic twist, which neither feels organic nor ingenious, Suryah only seems to be acknowledging that he couldn't come up with a satisfying end to the story he set originally out to film. All it does is give him a loophole to brush away the plot holes. Or, maybe, it his way of telling the whole world that SJ Suryah the director has literally woken up from his decade-long slumber.