Straight away, if you want to enjoy Mohenjo Daro, leave your disbelief by the door for Ashutosh Gowarikar's newest blast from the past only works as a fairy tale, not nailed in history, but hanging somewhere between Game of Thrones and Baahubali.
The film opens in 2016 B.C. with Sarman and Hojo and their friends, youths from the ancient village of Amri, travelling in a boat down a narrow river gorge. When attacked by a large man-eating crocodile, Sarman valiantly spears and kills it. They carry it back to the village where they are hailed as heroes. Sarman is unable to sleep: having lost his parents when very young, he is still haunted by a strange tune his aunt hums most days,l whom to trust. His uncle gives him an amulet to be used only in a life or death situation. (Sarman discovers that the amulet contains an inscription of the one-horned animal of his dreams, this animal is also the emblem of the city of Mohenjo Daro.)
Arriving in Mohenjo Daro to sell his wares (indigo) Sarman is stunned by the size and majesty of the city. Its markets attract Macedonian and Sumerian and foreign traders selling strange and exotic wares and animals (including the hitherto unknown horses). Sarman later discovers that Mohenjo Daro is ruled by the tyrant premier Maham and his wicked son Moonja. Maham proposes to levy an additional tax on the farmers; this proposal is supported by all of Maham’s cronies in the city council except the farm representative. The vote is passed and when the farm representative threatens to expose Maham – by revealing why Maham was banished from the neighbouring city of Harappa – Maham promptly kills him.
Sarman meets the beautiful Chaani, daughter of the head priest of Mohenjo Daro and the ‘Chosen One’ who will liberate the city and bring a new dawn. He leads the farmers of Mohenjo Daro to oppose Maham’s new taxes. (Maham’s soldiers threaten to kill him but Sarman, speaking for the farmers, says he prefers to die himself overpaying the higher taxes which will invariably starve his family.) He gains access to the upper city by brandishing his uncle’s amulet and, after saving Chaani from stampeding horses, he meets her father, the priest who, strangely, appears to recognize him. Sarman and Chaani profess their mutual love for each other but Chaani tearfully reveals that she has been forcibly betrothed to Moonja. After a dance at the new moon festival Maham realizes Sarman and Chaani love each other and that Sarman is the leader of the tax revolt. Maham is about to pronounce death upon Sarman but upon realizing the people are rallying behind him Maham demurs and shrewdly offers Sarman the Bakar-Zokhar challenge. Sarman proposes that if he wins then Chaani will be released from her engagement. It is accepted.
The head priest visits Sarman in his cell. He reveals how Maham was expelled from Harappa for illegally trading seesham (rosewood) trees with Sumerians. Maham entered Mohenjo Daro as a trader and quickly rose to become the trade chief in the city council. Maham had discovered that the mighty Sindhu river held vast gold deposits and so Maham proposed a grand plan to dam the river and divert its course so as to mine the gold and enrich Mohenjo Daro. The wise and upright premier Srujan opposed this plan but Maham somehow thwarted him and built the dam. Maham later had Srujan framed and falsely arrested for hoarding gold. With great remorse, the head priest recounts how he and Durjan (Sarman’s uncle) were threatened by Maham to oppose Srujan. Srujan was killed. The priest reveals that Sarman is Srujan’s son and it is up to him to purge the evil Maham.
Sarman faces the most ferocious Tajik mountain cannibals Bakar and Zokhar in a colosseum style arena. After a long and vicious battle, he kills one of the cannibals but spares the other and the crowds of Mohenjo Daro surge even stronger behind him. Maham is enraged and now urges Moonja to finish the priest and Chaani. Moonja storms the sacred temple and kills the priest and goes after Chaani. Sarman saves Chaani and kills Moonja.
Sarman leads the people back to the city council to challenge Maham. Chaani exposes Maham’s grand plan to use the gold from the Sindhu to enrich himself and to smuggle in brass and bronze weapons from the West. Sarman forces a vote of confidence in the city council where all the chiefs now stand against Maham. The people elect Sarman as the new premier but Sarman suggests Mohenjo Daro needs a people’s government, not a premier.
The Sindhu river, held by the slowly cracking dam, is about to flood. Sarman realizes that the dam will burst and the city will be submerged. As the river slowly breaks through the dam Sarman rallies the people to lash boats together and form a floating bridge. They all evacuate Mohenjo Daro and cross over the bridge to the other side of the river. The dam collapses and the river crashes into the city. Maham, chained in the city square, is drowned. The once renowned Mohenjo Daro is no more. Then the survivors migrate in search of a better place. The final scenes show them in another river basin, Sarman names the new river Ganga and the movie ends.