In 2126, Mu Xing has not allowed a murder to occur for thirty years.
Memory forensic expert Cen Wei received a death certificate that had not yet been issued: the deceased was Gu Linchuan, and the issuer was herself.
A few hours later, Gu Linchuan died in a laboratory that had never been unlocked. The medical examiner confirmed that he died as early as 20:05, but the surveillance video captured him walking out of the door at 20:08.
In his memory before his death, he saw his other self raising his hand.
When a second body with the same DNA and old injuries crashed back to Earth from the orbital cargo bay, Shun was not named as a relevant investigator. He can only find out a more troublesome problem than the murderer before his authority is taken away: which people in this world are counted as the same person.