This vastly interesting thriller takes place over several months in 1959-60 in Algeria, at the height of the struggle for liberation from France (1954-62). It would certainly be useful to familiarize oneself with the history of Algeria's colonization by France, and especially the fight for independence (at the very least, rent "The Battle of Algiers" which will get you in the right mood). The story centers on a French army officer who turns out to be an agent for the FLN, his exposure by his neo-fascist lover, and his attempt to go underground. The book is highly effective at showing both the underbelly of the fight for liberation and its flip side on the French side. It's also a believable portrait of a committed Marxist and his adversaries.