To give Kalavu Thozhirchalai its due, for almost half its duration, it makes us root for an anti-hero. This is Ram Sanjay (Vamsy Krishna), an extremely skilled smuggler, who comes to the village of Rajarajapuram to steal an emerald Shivalingam worth Rs 600 crore on the international black market. He poses as Suresh Chandran, a reporter from Malaysia, who has come to the place to film a documentary on temples, and gains access inside the temple where the idol is.
He also realises soon that stealing it might be more difficult than he had previously imagined and ropes in an accomplice, who he hopes will also be the fall guy in case things go wrong. This is Sweet Ravi (Kathir), a naive, small-time thief. Ravi, who is in love with Vani (Kushi) accepts mainly because he is about to marry the girl, and wants her to have a comfortable life.
But midway, the film turns into an investigative thriller, focussing on Irfan (Kalanjiyam), an officer from the economic offences wing who is tasked with the case of the missing idol. Does he capture the elusive Ram Sanjay, or does the criminal outwit the cop?
The best parts of Kalavu Thozhirchalai are the portions when Sanjay and Kathir try to steal the idol. These scenes are suspenseful and well shot, with the art direction by Murali Ram, especially, lending an authentic feel.
However, the rest of the film is more or less a let-down, turning what should have been a thrilling heist movie into a slow-moving film filled with unnecessary sub-plots. Even in the first half, Krishnashamy wastes too much time with the romance, which, he could have easily conveyed in the space of a song.
It is in the second half that the film truly unravels. The investigation scenes lack moments of deduction and almost everything that Irfan manages to discover feels like a coincidence. To make matters worse, the film abruptly stops for a song about football that has no place in this narrative. By the time we get to the end, we are quite exhausted to care.