Embarking on a journey across southern Poland to find his long-lost father, twelve-year-old Tomek receives help from a mysterious youth named Gabriel.

In the 1940s, a small band of underground paramilitaries attempt to fight back against the Soviet-backed security ministry in post-war Poland. Determined to fight for their country's future, the group goes to extreme lengths to make their voice heard.

Hubert is forced to confront his past during the premiere of a play by an old friend. He reminisces about a lost relationship and the choices he made in his youth, which constitute the titular “Kairos” – a turning point in life. Interweaving two timelines, the film explores themes of missed opportunities and the courage to live authentically.