Writer: Rohit Shetty
Ajay Devgn as Gopal
Tabu as Anna Matthew
Parineeti Jain as Khushi Bansal / fake Damini Jaisingh
Arshad Warsi as Madhav
Tushar Kapoor as Lucky
Kunal Khemu as Laxman/2
Shreyas Talpade as Laxman/1
Neil Nitin Mukesh as Nikhil Surana
Johnny Lever as Pappi Bhai
Prakash Raj as Vasu Reddy
Mukesh Tiwari as Vasooli
Sanjay Mishra as Babli
Vrajesh Hirjee as Pandu
Murali Sharma as Inspector Mukesh Dande
Vijay Patkar as Constable Gandhari
Uday Tikekar as Jamnadas Bansal
Sachin Khedekar as Colonel Chauhan
Ashwini Kalsekar as Damini Jaisingh
Nana Patekar as himself; voice of ghost
Mohan Ram as a ghost
Gopal (Ajay Devgn) who is afraid of ghosts, Madhav (Arshad Warsi), Lucky (Tushar Kapoor) who cannot speak, Laxman (Kunal Khemu) and Laxman (Shreyas Talpade) who has a speech impediment are orphans living in an orphanage in Ooty managed by a businessman named Jamnadas (Uday Tikekar). One night, the boys find a baby girl at their entrance and take her in, naming her Khushi. They take care of her and are also aware of librarian Anna’s (Tabu) ability to see ghosts and spirits. One day, when Madhav pranks and scares the timid Gopal in an empty bungalow, a fight ensues between the boys. Gopal gets punished, which prompts Gopal and Laxman to leave the orphanage and soon, Madhav, Lucky and Laxman also do the same. Khushi is later adopted by a colonel and his wife.
Some years later, Gopal and Laxman work with Babli Bhai (Sanjay Mishra) and Madhav, Lucky and Laxman work with Vasooli Bhai (Mukesh Tiwari). The group reunites after learning about Jamnadas’ demise. Returning to the orphanage after 25 years, they meet colonel, Anna and Pappi (Johnny Lever) another orphan from the orphanage who has frequent memory loss. They meet a girl (Parineeti Chopra) who they think is the bungalow’s caretaker, Damini and learn about the demise of the colonel’s daughter. At an event after Jamnadas’ funeral, businessman Vasu Reddy (Prakash Raj) reveals the orphanage would be demolished and moved elsewhere in plans to make his own building. When the group leaves the orphanage and returns, a ghost possesses Laxman and talks in Nana Patekar’s voice which scares Gopal. Next, the ghost possesses Madhav and prompts Vasooli to give them a task, indirectly bringing the three back to Ooty. A scared Gopal calls Anna who reveals that there is a spirit in their house and suggests him and Laxman to move to the colonel’s house. Upon reaching Ooty the two groups start fighting each other out of anger. The three try to scare Gopal into leaving the house but Gopal gets possessed and beats Lucky and Laxman badly. Later, Vasu Reddy assigns Madhav, Lucky and Laxman to burn down the colonel’s house. But things go awry when Lucky gets possessed by the spirit and starts talking which scares the group. The two groups then decide to leave but Anna and Damini convince them to stay for the birthday celebration and the group makes amends. The four find that Gopal has fallen in love with Damini and force him to confess his feelings. Pappi arrives and reveals that the girl they thought was Damini is actually Colonel’s daughter who is dead while the real Damini is his girlfriend. The boys get terrified and try to escape the house along with Pappi, Babli Bhai and Vasooli Bhai after Damini confesses it herself. Anna arrives and stops them and explains them that the ghost is none other than their childhood friend Khushi.
A flashback narrated by Khushi explains how her boyfriend, Nikhil Surana (Neil Nitin Mukesh), a young businessman, killed Jamnadas in order to obtain the orphanage in his name and demolish it for the construction of a site. Upon confronting him and threatening to go the police, Khushi was strangled to death by Nikhil. With the help of Vasu Reddy, he managed to prove the killings to be accidents. However, Khushi’s spirit came for help to Anna, who was surprised that the boys could see Khushi and eventually brought them to the house to help get justice for Khushi.
Back to present, Gopal thrashes the goons sent by Vasu Reddy while the rest of the boys, who wanted to stay away from the matter, get emotionally convinced to stay. They convince Gopal to stop chasing the goons and later almost manage to scare Vasu into confessing the truth, but Nikhil arrives before they can and reveals there’s no evidence to prove him guilty. This leads to a fight, during which Khushi attacks and nearly kills Nikhil but is calmed down by Anna, and Vasu convinces Nikhil to confess. With the orphanage saved, Khushi’s spirit departs to heaven after bidding goodbye to the boys and Anna.