Maida [Atiqah Hasiholan] is a young history student and a Christian who runs a free school for street children out of a Jakarta house. That house once belonged to Ishak Pahing [Nino Fernandez], a Christian Indo composer and pilot, and his Muslim wife Nani Kuddus [Imelda Soraya]; Pulau Tenggara ("The South-Eastern Island")—a song Pahing wrote—helped inspire President Sukarno to support the formation of the Non-Aligned Movement, all while they lived there. As Maida learns more about Pahing, she decides to write her undergraduate thesis about his life.
One day her class is interrupted by Sakera [Yama Carlos], a young Muslim architect who has been told to evict Maida's school by his employer, the developer Dasaad Muchlisin [Frans Tumbuan]. As Maida and Sakera argue in the streets, rioting breaks out around them. Sakera protects the half-Chinese Maida, and then vows to help her keep the house, even though it is scheduled for demolition within a week.
After attempts to persuade Muchlisin to keep the original design fail, Sakera overhears that the house sits on disputed land. Maida uses this information, along with feedback from a traditional musical group distantly related to Pahing, to discover that the house hides a secret underground bunker, where she and Sakera—with whom she has begun to fall in love—uncover documents that reveal the history of the house. With the help of her mother's former lover Kuan [Henky Solaiman], she learns the true ownership of the building.
Pahing, who grew up within the nascent independence movement and interacted with several historical figures, was arrested for being half-Dutch by the Japanese spy Maruyama [Verdi Solaiman]—a man who coveted Pahing's wife. After torture, Pahing is released to learn that his wife had been raped and killed; their newborn son Fajar had been kidnapped. Pahing later dies on a flight carrying medical supplies over Yogyakarta when the plane is shot down. Meanwhile, his son is raised by Maruyama and given a new name, Dasaad Muchlisin [Frans Tumbuan].
Armed with this knowledge, Maida, Sakera, and Kuan confront Muchlisin and show him how the house figures into his history. After a tense moment, Muchlisin tells them to leave. Several months later, on Maida and Sakera's wedding day—celebrated at both a mosque and a church—Muchlisin arrives at the church and reveals that he has abandoned his plans to demolish the house. Instead, he renovates the building and dedicates it as a school for street children.
