We live in an age of terror, an age where evil is inflicted upon the innocent in unprecedented events like the Mumbai blasts, Akshardham, the Parliament attack, to name a few. Col. Ranvir Ranavat (Ajay Devgan) is a soldier who lives by the code. He captures the mastermind of Al Tahir organization, Baba Zaheer (Mukesh Tiwari). Six months later, during a fierce skirmish at the Indo-Pak border, four terrorists cross over into India. Ranvir takes over the case and tries to trace these four men, their identities, their motive, their destination...their plan! In the meantime, in Mumbai, ACP Jai (Abhishek Bachchan) is tracking a gang which is trafficking arms into the city. In his pursuit of criminals, what Jai unravels is a Pandorals Box, leading him to the very corridors of power, where deception is not just from the enemy outside the border, but also from within. He also discovers the destination of the four men. It is a race against time as Ranvir arrives in Bombay to work with Jai and track these men. But they are too late. What unfolds is a plan so big, that will take these two men across our cities from the enemy. An enemy that is seen and unseen. 'Zameen' is a tribute to the courage of the Indian men and women who guard our borders and our cities from the enemy that is seen and unseen.