The Fundamentalist traces a 17 year old Ammar Dawar journey of transformation, from an average kid living in suburb Luton to a fighter in the ranks of most feared terror outfit in Syria. Ammar was born in a family, the Dawar's which had roots in Iraq, but were settled in UK for quite sometime. Ammar had exceptional brilliance, persona and talent which made him different from other kids.

He comes across his teacher and later a trusted friend, Jamal Khan during his time at Newport School and College. Jamal works endlessly as his teacher, and remained his sole support till the end. From the battle front in Deir-Az-Zor to Shadadah, the novel tracks Ammar every step till the end.