After investigation, it was learned that not all alien cities have a dragon. Among them, there are three alien cities located in the northern continent of Liamedo, the Great Western Current, and the Sahado Desert.

At the end of the year 2156, a joint mobile unit from the elite of various countries infiltrated an alien city in the north of Armedo, a mission that lasted for half a month, exploring the alien city about the size of seven football fields.

There is not a trace of energy reaction in this space city, so there is hardly any danger. The results of the survey were very shocking, and many plants belonging to the earth were found in the alien city. With the research of linguists from all over the world and professors and students of the linguistic studies departments of various universities, the documents found in the alien city were deciphered.

The literature says that about 7 million years ago, there was an intelligent civilization on the earth that was a creature roughly similar to that of modern humans, and this creature evolved for four generations, the first generation was a giant, with three eyes, and died of starvation. The second generation is smaller, can use the third eye to draw energy, and dies from magnetic field conversion. The third generation continues most of the abilities of the previous generation, and maximizes the abilities of the second generation, which can convert energy and die in floods. The fourth generation of humanity, which built the most developed civilization, died in ......... What he does best is alchemy.

This document confirms the existence of four of Earth's most famous human legendary civilizations. The only thing that puzzles all mankind is the last paragraph of the document about the cause of the demise of the fourth generation of humanity, which is completely ill-intelligible, and a large number of connected passages are blurred, as if someone had deliberately removed them. But what excites all mankind the most is the last paragraph of this document: the result of alchemy, alchemy steel has extraordinary power, which is the crystallization of the wisdom of the fourth generation of human beings, and condenses the power of the fourth generation of human beings, which is the greatest reliance on the invincibility of the fourth generation of human beings, and when alchemy steel meets some specific people, it will have magical power.

This undoubtedly brings a glimmer of hope to desperate humanity.

Countries jointly sent their most elite troops to the legendary fourth-generation human civilization city in the Atlantic Ocean to find the legendary alchemy steel, but the smooth sailing in the space city in Asia and America paralyzed them, and the absence of the sword does not mean that there is no danger; In a sudden situation, the sudden eruption of the ocean volcano damaged half of the submarines, and in the end only 150 people arrived at the Great Western Drifting Ocean Space City, and the elite troops encountered a special situation when they arrived at the Space City, and the energy of the Great Western Drifting Ocean Space City seemed to have the last bit left, and the suddenly activated defense mechanism destroyed one of the last two submarines, and the elite troops could only quickly complete the task and return to the surface.

The Great Western Ocean Space City was full of dangers, and multiple anti-invasion devices caused heavy casualties to the elite troops, but in the end, the remaining 20 people still found Alchemy Steel. There is a ton of alchemical steel in the Atlantic Space City.

Humans have crafted 400 pieces of alchemical steel into weapons. Through experiments, alchemical steel was able to cut through a three-centimeter titanium alloy plate. In 2158, known as the "Alchemy Strike Back Year", after a two-year break, humanity equipped the most elite warriors with alchemy steel, known as the "Alchemists", who reclaimed large swathes of lost territory. It wasn't until 2159 that humanity finally pulled back a game, and was in the same situation as Yu with a slight disadvantage. Humanity survives.