Who better than a former jihadist, Salafist near Yemeni and Somali leaders can explain from within the struggle between Western intelligence agencies and Muslim fundamentalist movements for over 15 years? Morgen Storm, a Danish national, recounts an eventful life: his erratic childhood and disorientation, her rocker in Islam then gradually in extremism, his doubts and his sudden conversion as a double agent for Danish and American secret services. This is a testimony of a man now hounded and threatened with death, who does not hesitate to tell as it was, with its good and bad sides. This is an opportunity to understand how Western young people who feel excluded from their society may be attracted by fundamentalist sirens and quickly falling into sectarianism and blind fanaticism. It is also a good way to understand the difference between the practice of a religion of peace, Islam, and drift of Salafism and precepts that bring us back to the first centuries after the Hijra. Incidentally, it is interesting to see how women are treated by fundamentalists. Both narrative and journalistic thriller, this dense book reads quickly and with interest.