The most precious things in the world are free, but ordinary people tend to turn a blind eye to them. Apart from air, sunlight, and familial love, there is still one more thing that’s extremely valuable. It’s right beside you and can be easily obtained.

This is a world dominated by summoners. In this world, summoners are the most dazzling protagonists on the center stage. When the mysterious and higher world becomes within reach, when the glory and memory of Chinese civilization shine into reality, the wonderful story of the summoner who came to the Great Yan Empire begins...

After the Catastrophe, every rule in the world was rewritten.

In the Age of Black Iron, steel, iron, steam engines and fighting force became the crux in which human beings depended on to survive.

A commoner boy by the name Zhang Tie was selected by the gods of fortune and was gifted a small tree which could constantly produce various marvelous fruits. At the same time, Zhang Tie was thrown into the flames of war, a three-hundred-year war between the humans and monsters on the vacant continent. Using crystals to tap into the potentials of the human body, one must cultivate to become stronger.

The thrilling legends of mysterious clans, secrets of Oriental fantasies, numerous treasures and legacies in the underground world — All in the Castle of Black Iron!