Huazhou Daily reporter Gu Zhuzhou received an emergency contact signal and rushed to the meeting point, only to see the body on the line. He burned the contact pad, emptied his pockets, turned around and walked into the door of the newspaper office - there was nothing strange on his face. No one can prove that he is an intelligence agent of the Morning Star Society. Under the rules of single-line communication, losing the line is equivalent to losing identity. The organization listed him as a missing person, and Naoki Miyamoto, an intelligence expert from the Super High School, smelled a flaw in him. A more deadly threat comes from his younger brother Gu Zhucheng, the leader of the military action team, who is tracking down the same lurker. Shen Jingtan is the only old liaison who can help him verify his identity, but using her means consuming this last connection and having to bear the risk of exposure. Liao Qiuhong is a newspaper colleague who accidentally discovered his code book; Song Yunzhi is an informant in the social circle, only recognizing money but not people. Gu Zhuzhou only had three cards in his hand that could be played. After each call, that person is permanently cut off from contact. He needs to use these three cards to send intelligence before the enemy during the attack and defense of the frontal battlefield. Use it once or less, and if you make one mistake, you will be doomed. How can a lurker without the support of an organization survive to the end?