What is it like to actually be an extremist and serve the political goals of radical Islam?
What is it like to think like an extremist and adopt an ideology that demands you abandon all aspects of your former life - including your friends and family?
Panorama: How I became a Muslim extremist. Monday 1 October 2030 BST BBC One
Shiraz Maher told his story on Monday's Panorama.
He is a former member of Hizb ut-Tahrir (HT), a radical organisation campaigning for the creation of caliphate - an Islamic state. It operates in many countries.
Shiraz made the case for a re-think of how the government should de-radicalise people like himself.
He told how after 9/11, he had a chance conversation with a HT member at a mosque and within weeks became a member of the cell.
The cell thought that democracy was incompatible with Islam, that the state of Israel should be destroyed, and that Shariah law should be imposed over the entire world with violence being used to achieve this.
Shiraz rose through the ranks to become a regional leader of HT.
It soon dominated his whole life - from refusing to go to family weddings because the women were not segregated, to recruiting as many people as possible to the cause.
Hizb ut-Tahrir filled a football stadium for their conference in Indonesia
While at Cambridge University he even tried to recruit Kafeel Ahmed into HT, who was later alleged to be part of the attack on Glasgow airport.
Shiraz has now 'come-out' and now wants to expose HT for the organisation it is.
HT Britain is trying to market itself as a conciliatory and moderate organisation that condemns violence as a means to achieve political ends.
With access to other former HT insiders, and HT literature the group wanted to keep hidden, Shiraz will revealed that HT Britain's conciliatory approach was merely a crude facade that concealed the same radical and extreme views.
Panorama: How I became a Muslim extremist, Monday 1 October, BBC One 2030 BST