The novel takes the form of journal-like anecdotes which the unnamed narrator claims to be writing to record his time in the war. It follows a squad of French volunteer soldiers on the Western front in France after the German invasion. The book opens and ends with broad visions shared by multiple characters but beyond these the action of the novel takes place in occupied France. In contrast to many war novels which came before it, Under Fire describes war in gritty and brutal realism. It is noted for its realistic descriptions of death in war and the squalid trench conditions.