On the same day that a terrorist attack brings London to a standstill, general practioner Dr. Mona Harcourt receives the devastating news that her brother, Dr. Kareem Shirani, has been kidnapped on his way home to the UK from his charity clinic in Lahore, India.

Mona returns to the UK and is determined to investigate Danny's suspected links to radical Islam despite her injuries. But her efforts to get Danny to safety on the day of Kareem's funeral have unexpectedly dire consequences for the family.