The story revolves around two families, whose patriarchs killed each other many years ago. Their respective sons, Jaswinder Randhawa and Balwinder Sandhu, are sworn enemies. Jaswinder has been in hiding in London, whereas Balwinder is waiting for his return in Punjab so he can avenge the death of his father.
In the present day, Jassi Randhawa (Ajay Devgn) is an unemployed good-for-nothing man who receives a letter from the Punjab government about buying his property in Punjab. To sell the property, Jassi leaves for Punjab. On the train, he meets and falls in love with Sukhmeet (Sonakshi Sinha). In Punjab, Jassi accidentally meets Billu (Sanjay Dutt) and, seeing he is new to the area, Billu invites Jassi to his home, where he treats Jassi like a God. There, Jassi realises that Billu is Sukhmeet’s brother. Soon enough, it is revealed that Billu is Balwinder Singh and Jassi is short for Jaswinder. However, Billu’s family has to follow one Punjabi rule: A guest in the house should never be harmed. Now, Billu must wait for Jassi to leave the house to kill him. Jassi learns about it and comes up with a hilarious plan to foil Billu’s shenanigans.