Raj Kumar Gupta, Sanjeev Kumar, abandons his girlfriend Shanti, Waheeda Rehman, to marry Kamini, whose father, Seth Din Dayal, Manmohan Krishna, makes him an equal partner in his business. After Gupta’s marriage, Shanti visits him to convey the news that she is pregnant with his child. She refuses Gupta’s offer of help, realizing that it’s only to soothe his guilty conscience, and she leaves the city. Shanti gives birth to a baby boy named Vijay and raises him as a single mother, determined to build a life for her son on her own terms.
Twenty-five years later, in 1978, Shanti passes away and the adult Vijay, Amitabh Bachchan, arrives in Delhi with a clear motive: revenge. He intends to ruin his father’s business and tear apart the Gupta family’s connections. At the same time, Gupta’s son, Shekhar, Shashi Kapoor, returns from abroad to stake his claim in the family company. Kusum, Kusum “Babli” Gupta, Poonam Dhillon, is his younger sister and also Vijay’s half-sister, and both siblings become entangled in the escalating war of power. Vijay’s path crosses with Geeta, Rakhee Gulzar, the loyal secretary to Gupta, who remains steadfast even as Vijay attempts to win her over with a bribe for information about Gupta’s tender bids. Despite Geeta’s refusals, a bond slowly forms between them, hinting at a complicated alliance.
Vijay’s schemes deepen as he bribes Bhandari, Yunus Parvez, to furnish him with inside details that Geeta cannot provide. Bhandari’s betrayal yields substantial profits for Shanti Constructions, widening the gulf of losses for Gupta’s company. When Gupta sees Vijay and Geeta together, he assumes Geeta has betrayed him and fires her. Vijay, learning of the misunderstanding, exposes Bhandari as the true culprit to Gupta and Shekhar, clearing Geeta’s name and offering her a role at his own company.
With his business acumen rapidly growing, Vijay hosts a lavish second anniversary party for Shanti Constructions and invites Delhi’s elite, pressing Geeta to help him extend influence, especially toward Gupta. At the celebration, he meets Sheetal Verma, Hema Malini, the daughter and general manager of P. L. Verma, who is also Shekhar’s girlfriend. Sheetal becomes a flashpoint in the rivalry as Vijay sows seeds of discord between Shekhar and Sheetal, fueling a broader clash between the families. The conflict intensifies as Gupta and Vijay sharpen their knives in a contest where both are willing to sacrifice wealth and integrity for victory.
Amid the tension, Kusum is encouraged by her lover Ravi to follow her heart, despite her father’s disapproval, and this personal drama further destabilizes the Gupta household. A furious Shekhar confronts Vijay, but Geeta intervenes and reveals a startling truth: Vijay is his older brother, bound to the Gupta family by blood in addition to his quest for vengeance. This revelation forces Shekhar and Kusum to leave their father’s house in shame, while Shekhar asks Vijay to give Kusum away at her wedding as her eldest brother, a gesture that intensifies Gupta’s anger and leads him to hire Balwant Rai, Prem Chopra, to eliminate Vijay.
The confrontation escalates as Vijay confronts Gupta about the past injustice endured by Shanti and his mother, revealing that Shanti has died and that Vijay is his and Shanti’s illegitimate son. Gupta is stunned and attempts to rescind the impending danger, but Balwant and his henchmen have already kidnapped Ravi to reach Vijay. With the help of Shekhar and Gupta, Vijay mounts a daring rescue of Ravi. In the ensuing showdown, Balwant fires at Vijay, but Gupta selflessly steps in and takes the bullet, dying in Vijay’s arms as the police close in on Balwant and his gang.
In the wake of Gupta’s dying plea for forgiveness, Vijay forgives him, and the two families reconcile. The film closes with a reconciled circle of love and ambition as Vijay and Shekhar agree to rebuild their legacy, renaming Vijay’s company Shanti-Raj Constructions in a tribute to the mother who started it all and the brother who stood by him through it. The story remains a sweeping saga of vengeance, forgiveness, and the enduring pull of family ties.
