It’s 1913, and the famous British author Rudyard Kipling is in the drawing room of his home in Sussex, England. In the dark, book-filled room, he helps his 15-year-old son, Jack, prepare for a meeting with military doctors later that day. Jack is nearsighted and can’t see without glasses, but Rudyard wants him to wear a pince-nez, thinking this will make him look dignified. Jack, however, hates the pince-nez, which keeps slipping off his nose as his father drills him with practice questions about why he wants to join the army.
Jack tries to talk about protecting England’s way of life against German invasion, but he gets too frustrated to go on, the pince-nez falling off and distracting him. Hearing his frustration, his mother, Carrie, enters and tells Rudyard to go easy on him, but Jack pretends to be fine. He then stands up straight and delivers a flawless speech about his desire to fight for his country, making Rudyard very proud.
At the Army Medical Board, Rudyard and Jack meet Major Sparks and Colonel Pottle. Sparks and Pottle want to ask Rudyard questions about his life, since they’re fans of his writing. But Rudyard directs their attention to Jack, wanting them to focus on getting him into the army. After a vision test, though, Sparks says Jack is too nearsighted to be a soldier. He and Pottle were ready to bend the rules, but they can’t in good conscience make such a big exception. If Jack lost his glasses in battle, he would be a danger to himself and other soldiers. Rudyard calls Sparks and Pottle cowards and storms out of the room.
That night, Jack talks to his older sister, Elsie, about the army, revealing that he only wants to enlist to get away from home. He feels stifled by the pressure coming from his father, which is so overwhelming that it makes Jack feel “sick.” Elsie doesn’t think Jack has to join the army just to get away, but Jack says it’s his best choice right now.
Three months later, Elsie returns from a trip to discover that Jack has managed to enlist. World War I has begun, so she’s worried about her brother’s safety. She peppers Rudyard with questions about how he managed to get Jack into the army, but Rudyard ignores her, looking out the window because Jack is due home for a visit.
When he arrives, Jack looks older and more confident, seeming to love military life. He’s a lieutenant with the Irish Guards and has spent the past few days marching nonstop. As he tells his family this, Elsie interrupts and asks how he enlisted after failing the physical examination. Jack explains that Rudyard’s influential friend pulled some strings. Elsie then learns that Rudyard pressured his friend to do this when the man was on his deathbed, making it hard for him to refuse. Elsie is enraged and worried, but Rudyard ignores her, believing that Jack is doing his country a great service.
A year later, Jack is in the trenches on the Western Front. It’s raining heavily, and he has taken it upon himself to help his men avoid getting trench foot. He inspects their feet, giving them powder and grease to apply as necessary. Two of his men, Bowe and Doyle, willingly show him their feet, but a confrontational soldier named McHugh refuses. He resents that Jack is a British Protestant commanding a group of Irish Catholics. Unfazed by McHugh’s animosity, Jack focuses on Bowe and Doyle, discovering that Bowe has a dangerous blister between his toes. He brings Bowe some dry socks and instructs Doyle to take care of him.
Meanwhile, the sound of artillery gets louder, as Allied forces bombard the German trenches in preparation for an attack. Not long before Jack and the others are supposed to charge out of their own trenches and rush toward enemy lines, Bowe pretends to be sick and tries to return to the dugout, but McHugh and Doyle won’t let him leave, forcing him to honor his soldierly duty. When the moment comes, Jack leads his men out of the trenches, McHugh and Doyle screaming as they go.
Back in Sussex, Rudyard receives a telegram informing him that Jack has gone missing in action. Carrie is beside herself, but Rudyard insists that this doesn’t mean Jack is dead—maybe he’s just lost. Carrie doesn’t listen, instead asking why Rudyard forced their son into the army. Defending himself, Rudyard insists that Jack did the right thing by enlisting and that it’s a great honor to protect one’s country. If Jack has died in battle, then his death will have been the brightest, proudest moment of his short life—something Rudyard wouldn’t want to have deprived the boy of by keeping him out of the military.
Two years later, Jack is still missing. Rudyard and Carrie have spent the years interviewing members of the Irish Guard about what happened on the day of his disappearance. Carrie is still going strong on this project, but Rudyard is exhausted. One day, though, a man named Mr. Frankland appears with a soldier who has new information about Jack. The soldier, it turns out, is Bowe. He is severely traumatized and has a hard time getting through his story, but he eventually reveals that he, Jack, and McHugh successfully made it to the German trenches on that rainy day (which is now known as the Battle of Loos). Once they were safe, Jack said they had to push on and attack a huge machine-gun post towering before them. McHugh called him crazy, but Jack blew a whistle, and the men ran out of the trenches for a second time.
The next thing Bowe knew, he was lying in a pit. McHugh yelled at him to retreat, but Bowe wanted to stay because Jack had been injured: the lower half of Jack’s face had been blown off. Unsure what to do, Bowe ran away with McHugh, at which point a shell exploded right where Jack was lying.
When Bowe leaves the drawing room, Rudyard tries to take comfort in the fact that Jack died bravely leading men into battle. Carrie refuses to see it this way, insisting that their son died a terrible death and that Rudyard’s patriotic ideas about duty and honor can’t change this. She even implies that Rudyard himself can’t possibly find comfort in these ideas, and he admits he’s tortured by the thought that he might be partially responsible for Jack’s death. He then breaks into tears, and Carrie says she feels “more dead than alive.” Regaining his composure, Rudyard promises that they’ll “manage” to get by despite this tragedy. And yet, he spends the rest of his life thinking about his terrible loss.
