When forensic doctor Chen Yan discovers the seventh corpse, shaped like a pottery figurine kneeling before him, in an abandoned factory on the outskirts of the city, he realizes that he is not facing an ordinary serial killer, but a madman obsessed with dark rituals. The deceased's abdomen was stuffed with yellow paper filled with different writings, and traces of fluorescent paint remaining in the gaps between his fingernails led the police to a high-end gallery - there, an abstract painting titled "Judgment Day" was dripping with wet "red paint" and signed with a twisted letter "C" in the corner.
As the investigation deepens, Chen Yan and veteran detective Xing Weiguo uncover a carefully planned four-fold sacrifice: "earth, fire, water, and sun", with every step pointing to deeper terror. The gallery owner Su Wanqing disappeared mysteriously, the artist Chen Xinghui was burned in a kiln, the kneeling figurines in the mud of the river bottom hid mysteries, and the final bloody stage was actually under the "Ruins of Light" of the abandoned observatory. The murderer used an inverted triangle as a mark and used paintings, blood and flames to construct his trial ceremony. Behind the truth, there was actually an old case that had been sealed for many years, and a vengeful soul branded with cross scars...
