A gas cylinder exploded, and Li Dejiang, an engineering student at Zhejiang University, transmigrated straight into the Tang Dynasty during the Zhenguan era, becoming the second son of Li Jing. He was also a foolish lad who had been “talking nonsense” ever since falling off a horse. He searched his whole body for his phone, tugged on Li Jing's beard to ask for the Wi-Fi password, and bowed to his father with a cheerful “Happy Father's Day!” From the moment he arrived in the Tang Dynasty, his life became one enormous comedy of errors.
Who could have guessed that the foolish boy had a knack for “cheating” the system? He could calculate the range of a trebuchet perfectly, then forget to account for the wind and smash his own family's grain stores. He improved the chain pump to save people from drought, but left the dimensions off his plans, then squatted on a field ridge and gestured alongside a carpenter to work out the changes. In search of potatoes that yielded “ten times more per acre,” he carried a sketch of a round lump all over Chang'an, mistaking turnips and sweet potatoes for his target and crying while clutching a turnip until the merchant caravan set out for the third time.
He caused even more trouble once he entered the court: he mixed gunpowder and blew up half a courtyard wall, hitting Qin Shubao's dog. Taizong rewarded him with sulfur and saltpeter, telling him to “keep playing.” He built a matchlock and blasted the emperor's teacup off the table, but his first thought was, “I need better iron.” He built public latrines and squatted nearby to keep a “manure fermentation ledger,” making officials take the long way around, but the latrines really did prevent an epidemic.
Later, he joined the army's campaign in the Western Regions, taking half a sack of potato seeds as provisions. He pursued the enemy into the desert, navigating by the stars, and after winning the battle, his first move was to grab the king and ask, “Do you have any crops that yield more than potatoes?” On a trip to the South Seas, he chased seagulls and nearly fell into the ocean. He taught the sailors to eat citrus to prevent scurvy, then forgot to eat any himself and ended up with bleeding gums. In East Africa, he saw a giraffe and wanted to ride it. He used potato seedlings as a “token of alliance,” somehow managing to plant the Tang Dynasty flag on the African coast.
While others fought over power and profit, he pondered putting steam engines on plows and equipping the Tang army with flintlock rifles.
