The Strange Guest of Zhenguan tells the story of Li Ye and Zhou Zhiruo, who are brought together by the study of natural philosophy and join forces on their adventures during the Zhenguan era. Combining the wisdom of natural philosophy with the way of martial arts, they unravel the mechanisms and conspiracies of the Heavenly Works Pavilion, resolve a celestial crisis in the Western Regions, and stabilize turmoil at court. They also use their ingenuity to improve everyday tools and spread natural philosophy far and wide. From chance encounters in the martial world to the shifting currents of the court, from a youthful first meeting to lifelong devotion, they use their combined talents to protect the homes and hearths of Chang'an. With warmth and wisdom, they write a legend blending patriotism, martial-world heroism, and the simple joys of life, revealing the truth that “understanding the world through its things opens the heart, and martial arts protect the living.”