A small country: President Qin, we’d like to import a batch of steel pipes and gas cylinders! Qin Feng: Sure. The instruction manual includes a structural diagram strictly prohibiting welding the two together!

A client: President Qin, we’d like to purchase a batch of fire suppression compression cannons! Qin Feng: No problem. The manual strictly forbids replacing the CO₂ hollow shells with thermite!

Subordinate: President Qin, we’ve bought back the Minsk! Qin Feng: Good. Proceed with the planned modifications—equip it with various types of drones. Our mission is to observe weather, hydrology, fish schools, etc. We’re converting it into a marine science research vessel!

Alternate title of the book: Sorry, We Really Only Produce Civilian Goods!

Chen Jian's time travel is different from others: they all travel to ancient times, but he possesses only animal skins and a stone axe. Starting from a matriarchal clan, he developed and perpetuated a civilization. Was it feudal statehood or unified prefectures and counties? Was it the distinction between the state and the wild, or barbaric conquest? Was it a hundred schools of thought contending, or a hundred saints uniting? Was it a single deity or a universal faith in ancestors? Was it a bloody accumulation of cotton silkworms cannibalizing humans? Or was it a humanistic care and a utopian dream of universal harmony? To enjoy the happiness of civilization, one must experience its pain. The ability to be reborn after death allows him to experience the growth of this civilization through a variety of identities. Tribal member, noble, slave, emperor, commoner, scholar, hired laborer, captain of the Age of Exploration, capitalist of the Age of Primitive Accumulation, conscript in the trenches, the mastermind of a major trust... With the same head in different buttocks, what kind of encounters and insights will arise?