《墮落騎士》敘述十字軍菁英聖殿騎士團的歷史。阿卡圍城戰過後，十字軍失去了聖地與聖杯。數年後，聖殿騎士團的宗師於巴黎神秘死亡，聖杯的下落因而出現了端倪，十字軍便前往尋找。《墮落騎士》所探討的是普世的價值，如信仰、奉獻、政治、愛與復仇，並揭發騎士、教會與腓力四世之間複雜而血淋淋的黑暗勾當，最後導致聖殿騎士團瓦解。
KNIGHTFALL follows the Knights Templar, the elite warriors of the Crusade, after the Fall of Acre in which both the Holy Land and the Holy Grail were lost. We join the Knights Templar years later in Paris, where the mysterious death of their Temple Master leaves behind a clue about the Grail and its whereabouts, sending them on a mission to find the lost Cup of Christ. KNIGHTFALL focuses on timeless themes such as belief, sacrifice, politics, love and revenge, and recounts the complex and bloody relationships between the Knights, the Church, and the Kingdom of Philip the Fair, and the dark events leading to the demise of the Templar Order.
