Ben Kingsley, who essays Perci Trachtenberg, widely regarded as the word's greatest living mathematician, meets Venkat, played by Amitabh Bachchan, a reclusive math genius from India, at a high rolling casino in London. Venkat tells Perci about an equation that could not only change the dialogue on mathematics forever, but one that has already left an indelible impression of guilt - for many painful reasons - on Venkat's life.
As it turns out, the reclusive genius Venkat has cracked a theory that could redefine the principles pf probability and randomness. However, as with all exceptional knowledge, his equation has its upside - as well as its dark underbelly. Aware that he is on the precipice of an extraordinary discovery, one that could find applications across various sciences, Venkat is encouraged to test his theory in the real world by professor Shantanu essayed by Madhavan (the super star from South India), an ambitious colleague of Venkat. Although Venkat has no interest in the money that could come from practicing his equation to crack Teen Patti, (a poker game) which could rake in all the moolah, he eventually succumbs to Shantanu's charismatic persuasion. Soon, with the help of a few students, each with a complicated and singular fate of their own, they explore the addas (underground gambling dens) of wild Bombay, and a series of edge-of-your-seat escapades keep the film moving faster than a bullet.
But what starts out as an experiment between a charismatic young professor and an eccentric older one soon descends into a game neither of them can control. When their lives sink into maddening chaos, the greed and desperation that had fueled them on can no longer save them.
As the film, super-slick and fast-paced, follows the escapades of each of the characters, all their lives secrets are laid bare, their motives exposed, and the darker side of the human heart illuminated with strobe lights of avarice and desperation. A tragedy occurs, which then sparks an investigation that not only threatens to destroy the careers of both Shantanu and Venkat but also eats into the very moral fiber of each of their being.
Now the film oscillates back to the casino in London. Convinced that Venkat's discovery has the originality and significance to change the narrative arc of mathematics, Perci understands that Venkat's theory in essence, questions the idea of what is random - and what fated. A surprising and deeply moving redemption, initiated by Perci, closes this stupendously modern film that is as much about the private equations of honor and change, and about knowledge that can change the world. But what if the price of this knowledge is life itself?