Four years ago, Bashir Shikder's wife Rashida flew from Florida to Syria with the couple's young children to join Isis, ignoring anguished Bashir's repeated pleas for her to return home. Now, after hearing news of his wife's death, and that his children – Yusuf now nine, and Zahra, five – are being held by jihadists in the last corner of the terror group's lands, Bashir travels to Iraq in the hope of crossing the border into Syria and rescuing them.