One morning in October 2013, nineteen-year-old Ayan Juma and her sixteen-year-old sister Leila left their family home in Oslo. Later that day they sent an email to their parents. 'Peace, God's mercy and blessings upon you, Mum and Dad ... Please do not be cross with us...'

Leila and Ayan had decided to travel to Syria, 'and help out down there as best we can'. They had been planning for months. By the time their desperate father Sadiq tracks them to Turkey, they have already crossed the border. But Sadiq is determined to find them.

What follows is the gripping, heartbreaking story of a family ripped apart. While Sadiq risks his own life to bring his daughters back, at home his wife Sara begins to question their life in Norway. How could her children have been radicalised without her knowledge? How can she protect her two younger sons from the same fate?

Åsne Seierstad - with the complete support of the Juma family - followed the story from the beginning, through its many dramatic twists and turns. It's a tale that crosses from Sadiq and Sara's original home in Somalia, to their council estate in Oslo, to Turkey and to Syria - where two teenage sisters must face the shocking consequences of their decision.