Shen Feng traveled to Chang'an City in the Tang Dynasty, the first year of Zhenguan.
Activate the check-in system and get a lucky draw every seven days.
After signing in for the first time, he received saltpeter and used it to make ice, which became a hit in Chang'an City and became a wealthy businessman.
After signing in for the second time, I received poems from literati, and accidentally became as famous as a great Confucian.
Signing in for the third time and getting a telescope made Li Shimin know that the earth is just a ball in the universe.
There are more and more things signed in, from steelmaking to munitions.
Until one day, the protagonist draws a 10,000-ton ship.
