Give the summary of the forth part of the book called gravel heart written by adulrazak gurnah ?

The first part of the book "Gravel Heart" by Abdulrazak Gurnah introduces the main character, Salim, and provides a glimpse into his childhood and early life in Zanzibar. Salim grows up in a small village with his mother, Amina, and his stepfather, Juma. His biological father, Rajab, left when Salim was young, leaving a void in his life. Salim's mother works hard to provide for the family, but they live in poverty.

Salim's childhood is marked by a sense of longing and a desire for a better life. He dreams of escaping the limitations of his village and finding success elsewhere. Salim's education becomes his ticket to a brighter future, and he excels in school. However, his dreams are shattered when his mother falls ill and dies, leaving him devastated.

After his mother's death, Salim's stepfather arranges for him to work as a servant for a wealthy Arab family in Stone Town. Salim's new employers, the Alidinas, are kind to him, and he quickly adapts to his new life. He becomes close friends with the Alidina's son, Abbas, and they spend their days exploring the city and dreaming of their futures.

As Salim grows older, he becomes aware of the racial and social divisions in Zanzibar. He witnesses the mistreatment of the African population by the Arab ruling class, which sparks a sense of injustice within him. Salim's desire for justice and equality becomes a driving force in his life, shaping his decisions and actions.

Overall, the first part of "Gravel Heart" sets the stage for Salim's journey from a poverty-stricken village to the bustling city of Stone Town. It explores themes of longing, loss, and the pursuit of a better life, while also highlighting the social and racial inequalities prevalent in Zanzibar.