Kostas Kazantzoglou, a refugee from Eastern Thrace, settles during the Occupation years in Thessaloniki, a city haunted by hunger, security battalions, and the persecution of leftists and Jews. There, he opens a shoemaking shop and soon turns it into a Resistance hideout. He meets the student Aris Anagnostakos, and together they organize their political struggle. Aris falls in love with Tasoula, Kazantzoglou's eldest daughter - a love that will pass through the flames of war and be tested. At the same time, a dark affair unfolds in Mount Athos. A Nazi mission seeks treasures - among them the Holy Grail. However, its leader, Byzantinologist Franz Delger, becomes trapped in the mysterious world of Athos as he faces the legend of the "invisible ascetics".
The City of the Innocent is based on true stories, on testimonies from the last living resistance fighters of Thessaloniki. Traveling through the dark continent of memory, it highlights the struggle of the unsung people who wrote modern history. At the same time, it sheds light from different angles on the harsh face of the 1940s, touching on issues that remain taboo to this day.