1420: The Ming Dynasty Time Traveler

In the 18th year of Yongle, Liaodong. An oak forest turned into blades overnight—leaves hardened like iron, cutting men when the wind blew, causing 17 casualties among Ming troops in three days. Qianhu Lu Chengzong was ordered to investigate and unearthed a pottery jar engraved with '1420' under the roots. The jar contained a liquid made of iron powder and grease. Not sorcery, but craftsmanship. Someone came from 400 years later, turning an agricultural society's war into a materials science experiment. That person is now hiding in the camp, watching Lu Chengzong dig up the first jar through the tent. The trees are innocent. The man may be executed. But what if he is also innocent?