R Srinuvasan, the director, establishes an excellent idea right away. We already know shankar will have one scenario that would cause him problems. But first, the director creates a compelling relationship between shankar and his dad, Subburayan (Marimuthu, who gets to portray an endearing role for once). For some reason, the young guy is not on talking terms with his widowed father, and their sole means of communication is through whatsapp voice messages. We get a sense of their connection in a few scenes. There is profound affection and respect beneath the superficial squabble. Subburayan offers cash to his jobless son, which is a nice touch.
The plot begins when shankar has a dream about his dad, a garbage truck driver, being involved in a collision. He tries to halt it, but, as in the first scene, he is powerless to do so. Subburayan finds up in the hospital, and shankar requires a large sum of money to get him treated. And the only way he can get it is if he uses his dreams to try to figure out who the hit-and-run driver is. On the advice of a kind hospital employee, he tries to relive his day in order to get the dream that will reveal who the enigmatic figure is.
Carbon, directed by R Srinuvasan, is a time-loop film in some senses. As in other films of the type, the hero is forced to relive a specific day again and over again. But then then, this isn't exactly a time-travel movie. In this case, the hero must consciously replicate the same day in order to attain his goal. But, unlike in time-travel movies, believing in this premise requires a leap of faith. For some, it may be as significant as the one shankar accepts after the hospital laborer's recommendation. But, thanks to some good writing, the director manages to persuade us to believe it.
However, on the flip side, despite discovering the identify of the driver and the purpose for the attempted murder, the police operate in a sloppy manner that stands out. Even the 'romance' parts, as well as Shankar's final decision, might have been written better. This is why the movie only feels watchable, despite the fact that it had the capacity to be genuinely fantastic.