My Sister-In-Law Is an Assassin

In the 21st century, Sui Jie, a soldier of the special forces, died in the line of duty. His soul traveled to a parallel world and committed suicide by biting his tongue and biting his tongue. Gu Yuezhen, the princess of the Mo Kingdom, happened to meet the eldest prince Mu Shang of the Su Kingdom who pretended to be the second son of the Jia family and sneaked into the Jia family. The two seemed to have a respectful uncle-sister-sister relationship, but in fact they both had an unknown side. During the day, she was the filial daughter-in-law of Jia's parents-in-law, but weak and could be bullied. At night, she was the Langzhou assassin who saved money to take her brother-in-law away. On the other hand, Mu Shang was the delicate and frail second son Jia Yi during the day, and the resourceful eldest prince of the Su Kingdom at night. Because a reward order for the assassination of the eldest prince was revealed at the end of the year, he ordered his sister-in-law to be surrounded and killed, and at the same time revealed his double identity. Two people with a hostile relationship end up in the same place by different paths? Or who will win?