Two immigrant brothers uncover the devastating truth about their German father's past, a Waffen SS officer involved in the Holocaust, after the younger brother reads the elder's suicide note and diary. The narrative follows Malrich, an aimless youth living in a Parisian housing estate, and his deceased brother, Rachel, whose diary entries reveal their father's role in Nazi atrocities. Malrich grapples with this legacy while drawing parallels between Hitler's regime and the rise of fundamentalist Islamism in his own community, creating a dual exploration of historical evil and contemporary extremism.

The German Mujahid is recognized as a significant work for its bold confrontation of the Holocaust from an Arab perspective, a feat described as unprecedented. Critics have noted the novel's masterful structure, employing alternating narratives between the younger brother's voice and the elder's diary to explore profound themes of guilt and evil. The author's perceptiveness in drawing parallels between historical Nazism and contemporary extremism has been a key point of discussion. The novel is lauded for its unflinching examination of complicity and the enduring weight of history on present-day lives.