Ismet Ulam Raja, a wealthy businessman, has three sons: Abdul Wahub P. Ramlee, Abdul Wahib S. Kadarisman, and Abdul Wahab Haji Mahadi. The brothers embody different temperaments: Abdul Wahab and Abdul Wahib are driven by wealth and enterprise, while Abdul Wahub leads a simple life, running a small music shop. On Ismet's birthday, he suffers a heart attack. Abdul Wahab and Abdul Wahib plot to inherit the family fortune, but Abdul Wahub urges his father to seek medical help; Ismet refuses. He passes away at home, and his wealth is split between Abdul Wahab and Abdul Wahib, leaving Abdul Wahub with only their father's house. Though disappointed, Abdul Wahub accepts the outcome and returns to his modest life.
Sadiq Segaraga, a friend of Ismet, schemes to claim the fortune. He orders his three daughters—Hamidah [Mariani], Rafidah [Dayang Sofia], and Ghasidah [Sarimah Ahmad]—to woo the three brothers. Hamidah and Rafidah succeed with Abdul Wahab and Abdul Wahib, but Ghasidah and Abdul Wahub clash.
Abdul Wahab and Abdul Wahib seek Sadiq's permission to marry his daughters. Sadiq agrees, on one condition: they sign a contract drafted by his lawyer Kassim Patalon [Salleh Kamil]. The contract states that if they lose their temper during the marriage, all their wealth will go to Sadiq, and they will be sold as slaves. Suspicious but hopeful, they sign.
After the weddings, they face harsh conditions at Sadiq's home, such as being barred from eating the food and sleeping in the stables. When the brothers lose their tempers, Sadiq enforces the contract, seizing their wealth and selling them as slaves.
Abdul Wahub witnesses his brothers being sold in the market but cannot intervene. That night, he dreams of his father's spirit, who directs him to Sulaiman Akhlaken, Ismet's overseas lawyer. Sulaiman reveals that Ismet's overseas properties now belong to Abdul Wahub, making him wealthier than his brothers combined.
Armed with his newfound wealth, Abdul Wahub proposes to Ghasidah. Initially skeptical of Abdul Wahub's financial standing, Sadiq agrees after seeing proof of his wealth. Sadiq presents the same contract, but Abdul Wahub counters with a second contract: if Sadiq loses his temper, Abdul Wahub will claim all of Sadiq's wealth and sell him as a slave. Sadiq reluctantly signs.
After marrying Ghasidah, Abdul Wahub encounters the same conditions as his brothers but remains unbothered. Over the next few days, he cleverly outwits Sadiq, avoiding Ghasidah, staging fake dates with another woman, and giving away items from Sadiq's shop to the poor. These antics nearly drive Sadiq to anger, but Kassim reminds him of the contract.
Eventually, Ghasidah confronts Abdul Wahub about his supposed infidelity. Abdul Wahub reveals it was all an act to frustrate Sadiq. He confesses his love for Ghasidah, and she admits she loves him too.
Sadiq finally loses his temper when Abdul Wahub invites the townspeople to take anything they want from Sadiq's house. Abdul Wahub reveals the contract, seizing Sadiq's wealth and selling Sadiq, Kassim, Hamidah, and Rafidah as slaves.
Later, Abdul Wahub buys back his brothers, Sadiq, Hamidah, and Rafidah, but leaves Kassim in slavery. Returning to their family home, Abdul Wahub delivers an emotional speech, apologizes for his actions, and releases everyone from the contracts. By the film's end, those who served as slaves learn the value of humility and kindness.
