The film follows Gustav Mahler Robert Powell and his wife Alma Mahler Georgina Hale as they travel back to Europe from the United States, aboard a train bound for Vienna. The crowds greet them at every station, but Mahler shuts out the speeches and bouquets, urging Alma to draw the blinds. Instead, the journey becomes a moving gallery of memories and visions, with each station and carriage stop sparking a new scene from the past or a projection of the future. On board, Alma's lover Max [Richard Morant] appears, pressing Alma to leave Mahler at a couple of stops before Vienna.
In a lakeside memory, a small hut serves as a makeshift studio where Mahler tries to compose while Alma rounds the lake, quieting animals and people and sharing beers to hush the world. A woman who swaps compartments with the couple notes that his newly written Ninth Symphony is about death, a thought that unsettles him. A doctor on the train tends to him after a heart attack, and he is revived, but the vision that follows shows him alive in a windowed coffin while Alma and Max ignore him as they carry on and eventually cremate him.
Other memories unfold: a visit to the Emperor of Austria about a music-director job, only to reveal that the scene is a delirious fantasy in which Hugo Wolf [David Collings] imagines himself as the Emperor, set in an asylum. In another episode, Alma longs to compose and Mahler’s lead singer performs a song of hers, but Mahler insists her true role is wife and mother, warning that composition is too stressful; he cites a mad friend and his brother’s suicide as cautionary tales, and Alma sadly buries her song in the woods.
Mahler’s conversion to Catholicism appears as a surreal baptism of fire on a mountaintop, presided over by Cosima Wagner [Antonia Ellis], whose influence in the music world is depicted through stark, provocative imagery—goose-stepping, a Prussian helmet, and a cross-embellished bathing suit with a swastika on the rear—reflecting the era’s dark currents.
In a final flashback, Alma is deeply upset when Mahler writes the song cycle Kindertotenlieder (Songs on the Death of Children). This memory is tied to the later real life tragedy, adding emotional weight to their dynamic. The on-train doctor, Doctor Roth [George Coulouris], confirms that Mahler appears to be in excellent health. Mahler tells Alma she must decide whether to stay with him or leave with Max at the next stop; he declares that all his music is for her, even claiming that the second theme of his Sixth Symphony is her. They kiss, and Max departs, while Alma stays aboard.
They arrive in Vienna, where the regular doctor informs them that Mahler is gravely ill with only a week or two to live. The train doctor relays the grim prognosis, but Mahler chooses a defiant optimism, insisting that he and Alma will live forever. With that resolve, they step into the station together, facing a future that art and memory keep alive despite time.