The emperor of the Cass Empire, Lyles, possesses extremely strong special combat power with his spirit beast and is currently the most outstanding beast master. However, his spirit beast also causes his body to be highly poisonous. Starting from the age of twelve, the toxicity has been uncontrollably overflowing and growing stronger year by year. When he was fourteen, even his breath was poisonous. After he turned seventeen, not a blade of grass could grow within a radius of one mile. To avoid causing innocent casualties, Lyles moved into the No. 13 Otherworld, which is full of fierce alien beasts, alone and has remained secluded for ten years since then. Three years ago, probably finally remembering that he had such a younger brother, the acting king Cass suddenly began to search for a spouse for him across the country. As soon as the news spread, it immediately caused a huge stir. Countless people flocked to it. After a selection that lasted for as long as two months, the groom headed towards the No. 13 Otherworld under the gaze of the public. One day later, he died. The second selection was in full swing. The selected groom was poisoned to death at the door before even seeing anyone. For the third selection, the number of applicants was zero. After that, the acting king Cass thought of countless ways, but no one survived. This terrifying invitation banquet of death has lasted for three years. It was two seconds after Amilo clicked the confirmation button that his mind slowly came to its senses. When he looked again, the advertisement pop-up window had disappeared. Five hours later, when the wedding procession blocked his company from all directions, even the cracks in the walls, he was finally convinced that the pop-up window was indeed a marriage application. Two days later, when standing on the No. 13 Otherworld, Amilo had only one thought: This was a fraud and he was going to report it. Carrying a highly toxic body, Lyles has long been accustomed to that kind of loneliness until one day, a man carrying large and small bags suddenly broke into his home, telling him that they were married and that he would sleep in his bed and eat his food.

The disaster erupted, and it was the end of the world. The survivors were tightly surrounded by impregnable walls, and a new order was established within the walls... Desire for power, faith, and darkness permeated each other, leaving deep imprints in every corner of people's hearts. The virus raged, and where was the true nature of people? "I don't want just to survive, I want to live." - Dian.