Han Yan, a modern engineer, accidentally became a craftsman of the Southern Song Dynasty's weapons supervisor, and faced death when he opened his eyes.
He used the drawings to improve the trebuchet, but was criticized as a "fantastic skill" and almost died.
On the way to escape, he met Li Wanzheng, an orphan girl from a general, and the two built an improved crossbow before the battle of Caishiji.
The Jin army pressed hard on the border, and the Song army was about to be defeated.
Han Yan directed the craftsmen to set up a secret weapon in the rainstorm: "Heavy Rain Pear Cannon."
Iron rain poured from the sky, the Jin Army pontoon collapsed, and history turned at this moment.
When the bad news of the destruction of Lin'an came, Han Yan raised the banner in Xiangyang.
Behind him is the roaring machinery, the burning fire of revenge.
This time, engineers have to reshape mountains and rivers with their own hands.
