Zheng Rui is an ordinary office worker at a regular company. One day, he suddenly falls into an endless nightmare of death. On the verge of a mental breakdown, he enters a mysterious world called Nightmare City. In Nightmare City, surviving means clearing nightmares, and those who do so are known as Dreamfallen. As a rookie Dreamfallen, how will Zheng Rui survive in this bizarre and fantastical world...