Watch on SFlix. There is a giant sinkhole in Guangxi called the Eye of the Underworld. According to folklore, it is the door to the Yin and Yang Realms. What's more, it is rumored that the ancient book "Long Guan Lu" containing strange recipes from past dynasties is hidden in the tiankeng. Ten years ago, during an expedition to the Eye of the Underworld, the entire expedition team headed by exploration expert Zhang Xiaotian died here. Ten years later, Zhang Xiaotian’s son Zhang Feng received a special express delivery, and the story unfolded...