David Cameron says seven terrorist plots have been thwarted in the UK this year alone. Mass casualty attacks, like those seen in Paris, are on the agenda too according to the head of MI5. What is going on in the communities from which this largely "homegrown" threat has emerged? In an attempt to understand, Edward Stourton gathers a group of Muslim journalists with grassroots knowledge of the British Muslim community. Contributors: Sabbiyyah Pervez Mobeen Azhar Fayaz Rizvi Secunder Kermani Producer: Sally Abrahams