Against the background of the Great European War (WWI), which creates a sort of vacuum of authority for those too young to be involved, a love affair is started between a sixteen-year-old boy (François, the narrator) and Marthe, a nineteen-year old young woman married to a soldier who is fighting in the trenches. They meet secretly in her flat on the outskirts of Paris. At first they try to keep their relation secret, but gradually they grow more and more brazen about it. They go shopping together and go out for walks or boating on the river. Both their families know about the affair, as do Marthe's landlord and the other people living in the flat building. Among their friends it causes a scandal. The only one who is blissfully ignorant is Jacques, the husband, whose letters to Marthe are burned by wife and lover together.
The narrator poses various insights about life and love, which are endearing in their coolness: "It was only now when I was certain that I no longer loved her that I began to love her," or "And yet love, which is selfishness in duplicate, sacrifices everything for itself, exists on lies." The feelings of François seem to be based on paradoxes, but neither he nor Marthe can bear to end the affair. Their passion leads to a climax when Marthe gets pregnant with the child of François (who speculates that he himself is still so young that having a child feels more like having a new brother or sister). She deftly manages to pass off the child as her husband's legitimate child even though everyone around them knows the truth. In the end, Marthe dies just after giving birth, probably because of a cold she caught earlier when François pulled her along to Paris at night, but was too shy to enter a hotel.
There is also humor in the story - one such scene is where the couple living on the floor below Marthe, who apparently are frequently harassed by their loud lovemaking, also in the daytime, arrange a party precisely so that their guests can catch the scandalous lovers in the act - except that François has noticed this and waits with embracing Marthe until the party has finished.
The title "The Devil in the Flesh" seems erotically charged (as in the film Flesh and Devil), but that is because of the translation. "Avoir le diable au corps" only means "to be furious, to quarrel with everyone" or "to be hyperactive" - two things said about teenagers as François. It was the sensational marketing of the novel by its first publisher that gave it a scandalous image, first and for all because of the denial of patriotism, of which there indeed is not a shred in the novel. Radiguet put love above all other concerns and maintains that it is the duty of each individual to follow the prompting of the heart regardless of what others say. The result is one of the most honest and moving love stories ever written.
There also is an autobiographical element in the novel - when he was only 14 years of age (!) Radiguet himself had an affair with an older woman whose husband was away at the front. But of course the story he wove around these elements from his own life is fiction.
The Devil in the Flesh has been adapted several times for television and the screen - most famous is the 1947 version (made after another devastating war) with Gerard Philipe.
My evaluation: 9 points out of 10. A tragedy that Radiguet died at 20 from typhoid fever. Despite his youth, he was active in Parisian art circles where he met Picasso and Gris. Jean Cocteau acted as a sort of mentor for him.
Audio book and text in French. Article in French. I read the novel as a Penguin Modern Classic.