In the spring of the 19th year of Yongle, three emperors in Yingtian Mansion died suddenly in a strange manner: the first deceased drowned in the Qinhuai River holding a "substitute contract", but there was no water stain in his body; the second deceased had his throat cut by an "invisible blade" in the Gongyuan dormitory, leaving only half a burnt page of "The Analects of Confucius"; the third deceased had a "≯" rune engraved on his heart, and a copy of the "Tiantai Academic Case" that was banned ten years ago was hidden in his arms.
Shen Yanbing, the commander of Jin Yiwei, was ordered to investigate. During the autopsy, he ran into female litigator Su Wanyue - the daughter of the core figure in the "Tiantai School Case" ten years ago. The two discovered that all the clues pointed to the upcoming exam: the "must-win kit" that the candidates received actually contained ink ingots made of dead people's hair; the waist badge of the Gongyuan invigilator had the same pattern as the Jin Yiwei Hundred Household Token that disappeared ten years ago; and the mysterious woman in red who appeared every time a crime occurred was consistent with the portrait of Shen Yanbing's late mother.
As the investigation deepened, Shen Yanbing discovered in prison that his father's interrogation records had been tampered with, while Su Wanyue deciphered the clue that "there is ironclad evidence of imperial examination fraud hidden under the mirror" from her mother's last words. When the two men uncovered the final mystery at the guillotine on a rainy night, they discovered that the real "soul-locking bureau" had already been laid: the names of all those involved had been engraved on the "Substitute Book" of the Yingtianfu City God's Temple ten years ago...
