After the Hungarian army is annihilated at the battle of Mohi, only a single fortress remains between the advancing Mongol forces and the rest of Europe. As the invaders reach its walls with overwhelming strength, the defenders—soldiers, clergy, and foreign fighters—prepare for a final, desperate stand. The unexpected arrival of a high-ranking envoy from Rome, the timing of the Mongol Lunar New Year celebrations, and the growing influence of spiritual practices within the fortress combine to offer the besieged garrison a faint but vital glimmer of hope.