As the novel begins, we meet Robert Ross, a Canadian soldier sitting with his hands between his legs while holding a pistol. Nearby, a building is in flames and a train is stopped. It is clear that a battle has taken place. Robert Ross is accompanied by a black horse and a black dog. Robert mounts the horse and is leaving when the horse neighs. There are other horses on the train; Robert decides to free them. Together, Robert, the horses, and the dog set out.
Robert Ross has enlisted in the Canadian army after the tragic death of his sister, Rowena. Robert was supposed to be looking over her when she died. Instead he was in his bedroom "making love to his pillows." After Rowena's death Robert's mother instructs him to kill the pet rabbits that belonged to Rowena. Robert tries to reason with his mother, but to no avail. Trying to ease the task for his wife and son, Mr. Ross calls a man named Teddy Budge to come to their home to kill the rabbits. When Robert sees Teddy Budge he tries to prevent him from killing the rabbits, but Teddy Budge beats Robert up. After the altercation Robert soaks in a tub, covered in bruises. He bruises easily. Robert's mother comes to talk to him while he soaks, causing him some discomfort as his privacy is breached. She knows that Robert has decided to enlist in the army to escape his guilt and to escape the morose atmosphere perpetuated by his parents' strained relationship. She tells him that she can't stop him from leaving and that if he wishes to go he can "go to hell." It is the last conversation they will have face to face.
Robert begins basic training. One day, while running, he sees a coyote and decides to follow it. It leads him to a small valley with a pond where he watches it drink. Later, it barks to him before leaving, signaling some kind of kinship. While looking for lost horses Robert comes across a war hero named Eugene Taffler. Robert believes Taffler may be able to teach him to have the will to kill another man.
Robert visits a brothel with other soldiers, though he would rather not. He succumbs to peer pressure and the knowledge that if he doesn't go it will result in suspicion. He meets Ella, a prostitute, and follows her to her room. She discovers that Robert has already ejaculated in his pants. She shows him a peephole where they can see into another room. Robert looks through it to see Taffler having sex with the large Swedish man who works at the brothel. Upon witnessing this, Robert begins to throw things in Ella's room, frightening her.
Robert ships out on board the S.S. Masanabie. The journey is difficult and unpleasant. Robert is called upon to kill a horse that has broken its leg down in the ship's hold. He has no desire to kill it but is one of the only men aboard armed with a pistol. He fires several times on the horse but does not kill it right away. Finally, frustrated, he unloads the entire weapon upon it, ensuring it is dead. Another man that Robert meets on board the ship, Harris, falls ill. Robert is also injured and relieved of his duties. He and Harris go to a hospital to recover.
Robert arrives in France and sets out leading a group of men on horseback. On a desolate road they encounter a thick fog. Robert proceeds ahead and falls into deep mud that seems to be everywhere. He manages to get himself out, though he nearly drowns. Robert eventually reaches the front lines with Poole, a bugler, and another man, Levitt. They proceed to a dugout where they meet Devlin, Bonnycastle, and Rodwell. Rodwell cares for injured animals he finds and has birds, rabbits, toads, and hedgehogs. The rabbits remind Robert immediately of Rowena. As a result, Robert builds a close relationship with Rodwell. We learn that Harris died two weeks before Robert left for France. Harris's body is mistakenly cremated. Robert meets Taffler again while at the hospital. Taffler is accompanied by a woman named Lady Barbara d'Orsey. Robert takes Harris's ashes to a river to scatter them there, knowing that Harris loved the ocean. He is accompanied by Taffler and Lady Barbara.
The German forces begin shelling and the dugout is hit. The men find themselves facing the horrors of trench warfare. Levitt's mind begins to unravel. Robert leaves the dugout and makes contact with Captain Leather, his superior officer. Leather orders Robert to position forward guns in a location that Robert knows will lead to certain death for any men stationed there. Robert is instructed to place the guns in a crater that is formed by the shelling. Robert climbs into the crater and slides down its slippery walls, injuring his knees. The rest of the men enter the crater and notice that the shelling has stopped. There is nothing but absolute silence.
The Germans launch a gas attack. Robert orders the men to don their gas masks only to find that none of them has one. He orders them to jump into the water in the crater. A struggle ensues to gain control of Robert's gas mask, the only one available to the men. Robert brandishes his pistol, restoring order. He orders the men to urinate onto a piece of cloth and hold this over their faces. The ammonia in the urine neutralizes the chlorine gas, saving them. They lay still, pretending to be dead for hours. Robert rises slowly and looks out over the crater edge where he sees a German soldier watching them. Rather than shooting the soldiers, the German allows all of Robert's men to leave the area. Just as Robert is leaving the German soldier makes a quick motion, and Robert turns around and shoots the German. Robert thinks that the German was reaching for his rifle when he was actually reaching for a pair of binoculars to look at a bird flying overhead. Robert also notices that the soldier had a sniper rifle right beside him, meaning he could have killed Robert and the rest of the soldiers if he had wanted to. Robert is haunted by the sound of the bird flying overhead.
The majority of the next section of the novel is told through transcribed interviews conducted with Juliet d'Orsey, Lady Barbara's sister. Robert receives an invitation to Barbara d'Orsey's residence at St. Aubyn's, a convalescent home. Eugene Taffler is recovering there. Juliet does not tell Robert what his condition is. When Robert sees Taffler, he sees that Taffler has lost both his arms in the war. He is shocked and saddened to see someone he once held in high regard fall.
Juliet also talks about Eugene Taffler's attempted suicide, which she inadvertently stopped. She walked into his room with flowers to find him trying to rub the wounds on the walls so that he would bleed out. Juliet alerted a nurse who came to stop Taffler.
Juliet begins to develop feelings for Robert, who, she has noticed, has grown closer to her sister, Barbara. One night she witnesses Barbara entering Robert's room and decides to play a prank on them by dressing up as Lady Sorrel, a woman whose ghost is rumored to haunt the room Robert is staying in. When she opens the door to Robert's room, she sees Robert and Barbara having sex. The act seems violent and unpleasant to her. She withdraws without going through with her plan. When Robert leaves St. Aubyn's to return to the front Juliet gives him a candle and a box of wax matches.
Robert's journey back to France is circuitous and long. Along the way he is separated from his kit bag, which contains his clean clothes and his pistol. After a long journey he finally arrives at Bailleul. He has no clean clothes and has not bathed, so he walks to Desolé, a bath house. After bathing there Robert is assaulted in a cell and raped by his fellow soldiers. He does not know who they were or how many of them there were. He returns to his room where Poole appears with his lost kit bag. After Poole leaves Robert takes the picture of Rowena that he keeps in his kit bag and burns it, reasoning that he would not want something so innocent to exist in a world like this.
Robert then moves back out to the front where he was before. The German shells have found their mark, landing in the trenches and killing men while burning everything else around them. Robert goes to speak to Captain Leather to request that the horses be let out of the barn because if the barn is hit they will all die. Robert reasons that they may need the horses. Captain Leather refuses Robert's request. Once back at the barn Robert enlists Devlin to help him release the horses. Devlin contemplates whether or not he should let all the horses die or face the wrath of Captain Leather. Devlin decides to help Robert and runs out to open the gate for the horses. Captain Leather gets up from beneath a table and looks out the window to see Devlin disobeying his orders. He runs out screaming at him to stop, and calls Devlin a traitor. Leather draws his gun and fires at Devlin, killing him. Then he sees Robert and takes aim at him; he starts firing but misses as Robert ducks between the horses as they are running out. At that moment three shells land in the yard, throwing Robert. When he stands up, he sees that the barn has been destroyed and the horses are dead or injured. Robert is overcome with rage. When he sees Captain Leather struggling to his feet, Robert shoots him between the eyes. He tears the lapels off his uniform and departs.
The scene returns to the prologue of the novel. Robert finds a black horse and a black dog beside it. As he is about to ride he realizes there are horses in the abandoned train; he frees a hundred and thirty horses and flees the area. As Robert is riding with all the horses a soldier attempts to stop him. Robert shoots him, too. Orders come in to a Major Mickle to pursue Robert and capture him. Robert is finally cornered in an abandoned barn with the horses he took. Major Mickle asks Robert to surrender. Robert, instead, fires upon him. Major Mickle orders his men to set the barn on fire in order to force Robert out. The barn goes up more quickly than expected and the roof collapses on some of the horses. Robert himself is set ablaze. Mickle's men get Robert out but he is badly burned. He is sent to St. Aubyn's to recover after being tried in absentia. A nurse, Marian Turner, takes pity on Robert and offers him a peaceful death. He refuses. Robert remains at St Aubyn's for the rest of his days, with Juliet d'Orsey at his side. He dies in 1922. Mr. Ross is the only member of his family to come see Robert buried.
As the novel ends, Findley focuses on a single photograph of Robert with Rowena atop Meg, a pony. An inscription on the back of the photo reads, "Look! You can see our breath!" Despite the negative imagery depicted in the book, Findley ends on a positive one invoking a sense of life and hope.