Those children

"When ten-year-old Ferzana Mahmud and her three older siblings lose their mother to cancer, everything changes. Their heartbroken father moves them from their familiar Chicago suburb to a city thousands of miles away in his native Pakistan. To help them adjust to life in Karachi and to the eccentricities of their extended clan, Ferzana, Fatima, Raza, and Jamila escape into a fantasy world of their own making. As superhuman creatures with incredible powers, they investigate the members of their grandfather's household. In the process, they discover astonishing facts not only about the Mahmuds but also about the nature of family, love, and loss in the troubled yet beguiling city that is now their home. Told from the perspective of an adult Ferzana reflecting over that fateful year, we see Karachi through the impressionable eyes of a ten-year-old child as she negotiates everything from religious schism and genealogy to patriotism and puberty. Ferzana's love of sleuthing helps her to piece together her family's complicated history, a history that brings with it the promise of hope and redemption"--Amazon.com