They call him The Jihad Hunter.
Dimitri Bontinck's teenage son had been introduced to Islam by a girlfriend, and soon became radicalised. One night the teenager snuck out of their home in Belgium and fled to Syria to join ISIS. Bontinck tried desperately to find him, and finally traveled to Syria himself to bring his son home.
Now he gets calls from parents all over the world who are desperate for the return of their own children.
Dimitri Bontinck's book is called Rescued from ISIS: The Gripping True Story of How a Father Saved His Son