In the year 1914, Vera Brittain seeks to break free from the constraints of her traditional family in Buxton by pursuing an education at Oxford University alongside her younger brother Edward and his friends, Roland Leighton and Victor Richardson. Despite her father's disapproval, she successfully passes the entrance exam for Somerville College. Before her journey to Oxford begins, Vera embarks on a romantic relationship with Roland, who shares her passions for writing and poetry; however, she is fully aware that Victor harbors feelings for her.
The world is turned upside down following the assassination of Archduke Franz Ferdinand, which marks the onset of World War I. Vera soon persuades her father to allow Edward to enlist in the army rather than attend university. Roland and Victor also enlist, with Roland becoming the first among them to face the brutal realities of the Western Front. As the casualty lists grow longer in the newspapers, Vera makes the brave decision to leave her studies and join the Voluntary Aid Detachment, offering her services as a nurse in an English hospital.
Though her friends perceive war as an adventurous undertaking, Roland describes to Vera the horrors faced on the battlefield. He proposes to her, and they promise to marry during his next leave. Roland ultimately returns to France, accompanied by Edward. However, while Vera eagerly awaits his arrival for the Christmas holidays, she receives devastating news from Roland's mother that he has been killed.
The army informs Vera and Roland's family that he passed away "a noble and painless death", but she demands the grim truth. George Catlin, who witnessed Roland's suffering in Louvencourt, reveals the reality of his agonizing death from a gunshot wound. Later, when Victor, now blind from his injuries, visits Vera's hospital, she offers her hand in marriage, feeling he will need someone, and knows that Roland would have approved. Victor, however, gently declines before succumbing to his own head injuries.
By 1917, as she yearns to be closer to Edward, Vera requests a transfer to France. Ironically, her first assignment has her caring for wounded German soldiers. Initially torn, she soon recognizes that these men, too, endure suffering. fate leads her to find Edward among the injured, where she plays a pivotal role in saving his life. He shares with her a letter from his "dear friend" Geoffrey Thurlow, hinting at a relationship beyond friendship. After Edward’s recovery, she is relieved when he is dispatched to the relatively safe Italian Front. Edward encourages Vera to resume her studies at Oxford following the conclusion of the war. Meanwhile, back home, Vera faces the emotional challenge of dealing with her mother’s nervous breakdown. It is here she uncovers the heartbreaking telegram announcing Edward’s death, which she learns of through her father's grief.
In 1918, engulfed by the loss of those dearest to her, Vera cannot find joy amidst the celebrations of the Armistice with Germany. Back at Oxford, she struggles with haunting nightmares concerning the deaths of both Roland and Edward. Winifred Holtby, a fellow student, provides the support Vera desperately needs to handle her trauma.
Attending a public meeting discussing punitive measures against Germany, Vera listens as most of the audience opposes George Catlin, who cautions against the philosophy of revenge. Burdened by feelings of guilt for encouraging her father to let Edward enlist, Vera openly shares her experience of comforting a dying German soldier—who was, in essence, no different from her brother or fiancé. She asserts that the deaths of these young men hold significance only if they collectively reject the cycle of violence: > "No" to war and revenge.
Vera emerges from this trial as a pacifist, making a solemn promise to the fallen souls that their memories will forever be honored. The film concludes with a poignant dedication to those who sacrificed their lives in the war.
While the film closely adheres to the narrative of the original book, it also diverges in key aspects. George Catlin, who joined the army in 1918, never crossed paths with Roland, who perished in 1915. Additionally, Vera did not directly assist in saving Edward's life; rather, he was sent to the First London General Hospital where she served as a volunteer nurse. Also noteworthy is the mention of the looming Spanish flu while Roland departs for war in 1915, despite the pandemic only emerging in 1918.
