In 2024 Poland, Old Danka sits in her study, reflecting on her childhood through a vintage notebook filled with sketches and memories. The story then transports us back to 1944 Ukraine, where young Danka lives with her family in a peaceful village surrounded by sunflower fields. Her grandfather, Antoni, introduces the entire village, their love for each other, and local unity, in a musical sequence.

The tranquility is shattered when Soviet bombers attack the village. Antoni hurriedly hides Danka under the bed, turning their nightly game of hide-and-seek into a grim reality. The family is forced to scatter, with Danka's mother, Alicja, and sister, Hela, seeking refuge elsewhere. Antoni is tragically killed by Soviet soldiers, leaving Danka traumatized but determined to survive.

The narrative follows Danka as she clings to a magical sunflower, believing it holds the key to reuniting her family. The sunflower, which glows and responds to her emotions, becomes a symbol of hope and resilience.

The family flees on a crowded train heading west, leaving their home behind. During a brief stop in the countryside, Hela, Danka’s older sister, leaves the wagon to find water but is tragically left behind when the train departs without her.

On the train, Danka meets Oleg, a Soviet boy traveling alone with his rooster, Boris. Despite their different backgrounds, they form a bond and navigate the hardships of their journey together. Oleg reveals his own tragic backstory through a poignant flashback sequence, where we learn that he lost his parents due to political repression under Stalin’s regime. This scene is underscored by a haunting lullaby that his father once sang to him, blending with the sounds of the wheat fields from their farm.

Oleg introduces Danka to a Mystic Lady who explains to them that the sunflower might be losing its powers along with lost hope in the family.

Danka and Oleg, determined to find Hela, use the sunflower's guidance to navigate through the train's compartments. They eventually reunite with her, which leads into a musical sequence in a transformed bar wagon, where the passengers, led by the magical sunflower, engage in a lively celebration. The train car becomes a scene of dancing and singing, offering a brief escape from the harsh realities outside. However, their joy and relief are short-lived as the train is attacked again.

Boris notices two armies—Soviets and Germans—approaching each other and decides he must rejoin the Soviet army to stay loyal to Stalin. He steals the sunflower and runs away. Danka and Hela rush to the locomotive only to discover that the train has encountered a blockade on the tracks, threatening to derail them. Danka, Oleg, Hela, and the other passengers quickly unite to remove the obstacle. Oleg eventually returns, bringing both Boris and the sunflower back, while Hela rescues their mother from one of the wagons.

After they finally manage to continue the journey, they face one final challenge. They must divert the train to head toward a new village rather than into a war zone. Oleg takes heroic action by jumping off the train to manually change the track, ensuring their safety.

The story concludes with the train safely reaching its destination where the community from the train forms a new village in a previously abandoned town. Oleg rejoins them in the Church while the Sunflower regains its colors but stays enclosed in the painting in the Church.

Danka, in the present day, closes her notebook and visits the Church to leave a candle by the Board listing all the people killed in 1944. The Sunflower gives her a final wink.