Senior correctional officer Man Sheung Shing is stationed at the Stanley Prison and is in charge of prisoner discipline. Clashing with prisoners every day, he is under heavy pressure and must act carefully every step of the way. In contrast, his subordinate Kiu Ching Kiu frequently ignores the rules and has close contact with the prisoners, even developing a relationship with one of them. This causes a lot of tension between them. Yiu Ngoi Ka, who works at the Lo Wu Correctional Institution, has known Sheung Shing for many years. Despite their ten year age gap, she bravely expresses her love for him, but is met with his swift rejection. The ordeals inside and outside the prison cell lead to complicated stories that most people cannot understand. With a large riot waiting to break out, Sheung Shing and his colleagues' lives are put into danger.