The Inspector Wasan, a cop under investigation by internal affairs but called back to duty to investigate the murder of a minister's daughter. He's joined in the investigation by Sergeant Thong and the young female officer Lieutenant Nalin, whose investigative style is the opposite of Wasan's. Meanwhile, the killer has Wasan in his sights, setting out to ruin him by exposing his role in a previous case.

"My duty is Drag the murderer."