The Public Security Bureau intercept a telegram notifying foreign agents to retrieve the "110 secret". Shi Yan, head of the Reconnaissance Section, starts a campaign of counter-espionage, but one of his agents is soon killed on board a train.
| Actor | Role |
|---|---|
 Lei MingShi Yan | Shi Yan |
 Ling YuanYu Huangshi | Yu Huangshi |
 Liu JiaYu Qiulan | Yu Qiulan |
 Ping ZhangHong | Hong |
 Bi JianchangLu Deqin | Lu Deqin |
 Qin WenLiu | Liu |
 Cao CuifenNot listed | Not listed |
 Zhang YanNot listed | Not listed |
 Fang HuiNot listed | Not listed |
 Lin LiNot listed | Not listed |
| WWang HuimingNot listed | Not listed |
| LLi LaoNot listed | Not listed |
| ZZheng LinNot listed | Not listed |
 Wande ZhaoNot listed | Not listed |
 Jian LiNot listed | Not listed |
| CCheng XueqinNot listed | Not listed |