The Lowland is a sweeping, ambitious story that examines in intimate detail the intersection of the political and the personal, encompassing nearly 50 years of Indian and American history through the lives of one family. The novel ripples out from the beginnings of the Naxalite uprising in West Bengal in 1967. Two brothers, Subhash and Udayan Mitra, are attracted by the radical communist movement while at university in Calcutta. But Subhash, the more cautious and sensible of the two, quickly perceives the danger involved and withdraws, leaving to study in the US. Udayan, left behind, becomes more entrenched in militant politics, believing that violence against the state is justified in the name of revolution. It's not much of a spoiler to reveal that, early on, he is arrested and executed by the police on the lowland behind their parents' suburban house, supposedly for his part in a violent crime.

"Udayan had given his life to a movement that had been misguided, that had caused only damage, that had already been dismantled. The only thing he had altered was what their family had been." The novel pivots on this moment of Udayan's death. He leaves behind a young widow, Gauri, a fellow student already in the early stages of pregnancy. Out of a sense of duty to his brother, and to save her from a life of drudgery in Calcutta, Subhash marries Gauri and takes her back to Rhode Island. There, for the sake of propriety, they maintain the fiction that he is her daughter's father, though the lie slowly corrodes their fragile marriage.