Tonight marks the final part of Peter Kosminsky's powerful drama, which kicked off on Sunday and has aired every night since. It follows a group of British men and women who have been radicalised and travel to Syria to join Islamic State. In tonight's finale, Jalal is given a new role by Isis and witnesses barbaric punishments and mock executions to feed its propaganda machine. Meanwhile, as Ushna's commitment deepens, Shakira's concern that Isaac is being readied for frontline battle makes her contemplate the unthinkable - whether there is any way out of The State.