Takht Hazara is a pleasant place on the banks of the river Chenab. It is the abode of the Ranjha clan who lives here in contented luxury. Mauju Chaudhri is the chief landowner and he loves Dhido, lovingly called Ranjha, more than his other sons. After Mauju's death, due to ill treatment of his brothers, Ranjha leaves Takht Hazara. On the riverbank, he accidentally meets Heer, the daughter of Mehar Chuchak Sial of Jhang, who is as lovely as the moon.
Ranjha takes up the job of a herdsman with the Sials, a renowned tribe of the area. He is extremely good at playing the flute and melodious music flows whenever his lips touch the reed. Heer and her friends go to the forest every day to hear the mellifluous music. She becomes mesmerised with the way he plays the flute and soon they are tied in the bond of love. Time passes happily. However, one day the lovers are caught out when Kaido, a crippled uncle of Heer, comes to know of their love after watching them together in the forest. He instigates Heer's father to find a suitable match for her.
Chuchak is determined to marry off Heer to avert disgrace, but the Sials have never given their daughters to the lowly Ranjha tribe. However, soon a suitable match is found. He is Saida of the Kheras who lives in Rangpur.
The Kheras are overjoyed and ask the Brahmans to consult the stars and to fix the marriage. Virwati (Thursday) in the month of Sawan comes up as the best day for the wedding. Heer opposes the marriage and declares it illegal. Nevertheless, she is married by force. Heer languishes in the house of her father-in-law Ajju Khera. She refuses to put on jewellery or gay clothes, declines food and lies awake all night thinking of Ranjha. Sehti, her sister-in-law, wins her over and makes her tell the secret of her heart. Heer narrates her story and Sehti consoles her saying that she too has a lover, Murad Bakhsh, a camel driver, and that somehow they must contrive to help each other.
After a year, a Jatt girl from Rangpur returns to her home in Jhang Sial. She bears an urgent message for Ranjha: Heer is on the point of death. Ranjha resolves to become a fakir and sets off for Tilla Jogian, the hill where Balnath the Jogi dwells. There he is granted Jog. Once in the village of the Kheras, he takes up a beggar's bowl and goes from door to door crying for alms. Luck brings him to the house of Ajju Khera. A slanging-match with Sehti brings Heer to the courtyard. She glances at the Jogi and behold! It is her lost lover.
After that Ranjha installs himself on a hillock in the garden of Kalabagh where Heer goes to meet him. Later, Sehti and Heer consult how Heer may leave the Kheras and be united with Ranjha. The next day they go to the garden where Sehti bites Heer's foot and they pretend that a snake has bitten her. The Kheras summon fakirs, hakims and enchanters who give her cunning drugs. But Sehti tells them there is a very ingenious Jogi in the Kalabagh garden in whose flute there are thousands of spells. Ranjha is brought and lodged in the hut belonging to the village minstrel. That night Murad takes Sehti on his camel and Ranjha takes Heer. Thus the bridegrooms set forth with their brides.
The Kheras draw up their armies and succeed in overtaking Murad, but the Baloch drive them back. But destiny overwhelms the other pair of lovers for the Kheras find Ranjha and Heer asleep. They take away Heer and give Ranjha a vicious beating. Ranjha seeks justice from the king whose armies bring the Kheras to the court. After hearing both the sides the king hands over Heer to the Kheras.
On hearing the judgment, the lovers invoke curses on the city owning to which it catches fire. The astrologers tell the king to conciliate the lovers. So the Kheras are brought back and he tells Heer that she may go with her rightful husband.
Heer returns to her parents' home, as she desires to enter Ranjha's family with proper marriage rituals. But Kaido makes a resolution to poison her. On the day of Heer's departure, Chuchak embraces her. Over his shoulder she hears Kaido's soft voice urging her to eat a sweetmeat before she leaves.
She responds to his poignancy and takes a piece that he offers. Meanwhile, a messenger arrives in Takht Hazara and breaks the news to Ranjha that Heer has been posioned and therefore dead. He quietly slips into a room and kneels down to pray. Hours slip away, darkness gathers. The crowd in their vigil begins to grow restless. One of them gathers courage and goes inside the room. As he touches Ranjha's shoulder he falls down dead.
Today people come from afar to pay homage to the lovers whose story is a concoction of fact and fiction. They tie strips of cloth to the window of the room chamber hoping that through this act their love will be fulfilled.
Heer and Ranjha lie in eternal sleep in a common grave shaped like a cot and covered with tiles inside a room which, a signboard of the Punjab Auqaf Department says, is the court of Hazrat Izat Bibi alias Mai Heer Sial and Mian Murad //Bakash// alias Mian Ranjha. The dome has an opening in the middle but it is said that rain does not enter into the chamber - a miracle attributed to the lovers - notwithstanding the raindrops found inside after a light shower.