Throughout the film, the passage of time is marked by title cards featuring dates, accompanied by a Medieval cavalcade in the background. On New Year's Eve 1899, the affluent couple Jane (Diana Wynyard) and Robert Marryot (Clive Brook) arrive home at their London townhouse to uphold their tradition of toasting the new year. Jane expresses her worries as Robert, who has signed up to be an officer in the City of London Imperial Volunteers (CIV), is set to depart for the Second Boer War, where her brother is already engaged in battle. Their loyal butler, Alfred Bridges (Herbert Mundin), is also leaving for war as a private, prompting concern from his wife, Ellen (Una O'Connor), and her mother, Mrs. Snapper (Tempe Pigott), who fear for the well-being of Ellen and their infant daughter, Fanny. Despite the impending dangers, Alfred remains optimistic. At the stroke of midnight, the Marryots and Bridges families raise their glasses to welcome the new century.
Following this, Jane and Ellen share tearful goodbyes with their husbands as they embark on the same ship. Keeping Jane company is Margaret Harris (Irene Browne), who provides support while Robert is away. During a night at the opera, excitement breaks out as the relief of Mafeking is declared from the stage, leading to an uproar of applause. Upon their return, Robert is knighted for his service. With his newfound fortune, Alfred shocks everyone by announcing that he has purchased a pub—his and Ellen's ticket out of service life, marking a new chapter for them and their family.
Fast forward to 1908, the story tightens as Alfred's struggle with alcoholism spirals, leading to the mismanagement of their pub, all while he squanders the family's rent money on drinks. Ellen and Fanny ([Bonita Granville]) are left to bear the weight of Alfred's disgrace. To regain some dignity, Ellen meticulously orchestrates a gathering with the Marryots, who are now eager to visit. Despite planning to keep Alfred in the dark about the occasion, chaos ensues when he drunkenly bursts in, vandalizing Jane’s gift to Fanny—a cherished doll. In a heart-wrenching turn, Fanny flees outdoors, and Alfred’s reckless pursuit results in a tragic accident involving a horse-drawn fire engine, claiming his life.
On July 25, 1909, while at the seaside, Ellen and Fanny happen upon the Marryots. Ellen shares how she has taken over the pub and that Fanny, now blossoming into a remarkable dancer and singer, supports their endeavors. Meanwhile, Edward, now attending the University of Oxford, is smitten with his childhood companion, Edith Harris ([Margaret Lindsay]). The families witness the historic victory as Louis Blériot completes his groundbreaking flight across the English Channel.
As the timeline progresses to April 1912, Edward and Edith have wed and are luxuriating on their honeymoon aboard the ill-fated RMS Titanic, a fate only hinted at later in the dialogue. The scene shifts again with the onset of World War I in 1914, as both Robert and Joe ([Frank Lawton]) enlist, naïvely believing that the conflict will resolve swiftly. During his leave, Joe reconnects with Fanny ([Ursula Jeans]), who is captivating audiences in a nightclub. Their relationship flourishes amid the chaos and danger of war, culminating in Joe’s heartfelt proposal, but Fanny’s hesitation stems from their stark class differences.
The conflict escalates, leading to an agonizing moment in 1918 when Jane is struck by the news of Joe’s death in battle, just as Ellen confronts her about Joe's relationship with Fanny, beseeching her to ensure they marry. Racked with grief, Jane wanders through the armistice celebrations in Trafalgar Square, overwhelmed by loss.
The film concludes with a montage showcasing the upheaval of daily life and the shifting social order, as voices rise calling for peace. The final scene brings us to New Year's Day 1933, where an elderly Jane and Robert continue the cherished tradition of toasting the new year, reflecting on their past and hopeful for the future.
