The Narrator is an unnamed 18-year-old Canadian recruit from Quebec. Serving as a stand-in for all young soldiers, he begins his journey with romanticized notions of combat but quickly confronts the harsh, dehumanizing reality of trench warfare. His experiences show the profound psychological and physical toll of World War I on the common foot soldier, as he transitions from an eager recruit to an exhausted, hypervigilant survivor.

Anderson is a middle-aged, deeply religious soldier from Ontario and the oldest man in the Narrator's unit. He relies heavily on his Christian faith and scripture to endure the horrors of the war. He serves as an opposite to the younger, more debauched soldiers around him, frequently praying and reading the Bible to maintain his sanity in the trenches.

Broadbent is a lance corporal and the most experienced soldier in the Narrator's unit. He takes on a pragmatic role, often attempting to educate the newer men to help them survive the brutal realities of trench warfare. While he provides leadership, he is still an enlisted man who feels the same hunger and exhaustion as his subordinates, sometimes squabbling over basic rations.

Brown is an enlisted soldier who operates a farm on Prince Edward Island, where his wife awaits his return. He is not the most naturally adept soldier, making him a frequent and unfair target for Captain Clark's sadistic punishments. He brings a touch of civilian humanity to the trench by frequently regaling the men with stories of his honeymoon.

Fry is a vocal and deeply embittered member of the Narrator's unit. He openly expresses his disgust with the military leadership, resenting the officers who demand everything from the soldiers—including their rest time—while offering little support in return. His anger gives voice to the collective frustration of the enlisted men.

Captain Clark is the tall, blond, English commanding officer of the Narrator's unit. He takes immense pride in his spotless uniform and sadistically bullies the enlisted men. He imposes strict rules on them, such as demanding daily shaves in freezing conditions without hot water, demonstrating a complete lack of empathy for the common soldier.

Gladys is a civilian woman the Narrator spends time with while away from the front lines. She accompanies him to a vaudeville show, but her inability to comprehend the gruesome reality of trench warfare—and her dismissal of the psychological weight of killing an enemy soldier—only deepens the Narrator's sense of isolation from the civilian world.

Renaud is a young French Canadian recruit who joins the Narrator's battalion later in the war. Like many of the enlisted men, he struggles under the immense physical strain of marching with heavy gear, making him yet another target for the officers' physical cruelty.

Cleary is a fellow soldier in the Narrator's unit. He is a trusted comrade whom the Narrator relies upon to hold his personal effects and identification papers when facing the strong possibility of death during a volunteer combat mission.