Fourteen-year-old Maryam and Zahra have always been the best of friends, despite their different backgrounds. Maryam takes for granted that she will stay in Karachi and inherit the family business; while Zahra keeps her desires secret, and dreams of escaping abroad.

This year, 1988, anything seems possible for the girls; and for Pakistan, emerging from the darkness of dictatorship into a bright future under another young woman, Benazir Bhutto. But a snap decision at a party celebrating the return of democracy brings the girls' childhoods abruptly to an end. Its consequences will shape their futures in ways they cannot imagine.

Three decades later, in London, Zahra and Maryam are still best friends despite living very different lives. But when unwelcome ghosts from their shared past re-enter their world, both women find themselves driven to act in ways that will stretch and twist their bond beyond all recognition.