Four officials go missing in the Qian Kingdom, and two turn up dead in a similar fashion as in a Qi nursery rhyme. A Qi suspect is apprehended for questioning, and Su Jiu Er, who suffers from a cold disease, and her godfather, Hu Ba Dao, are chosen to interrogate him. Things go quickly awry when the suspect, Han Zheng, escapes with half the case file. Jiu Er and Ba Dao are forced to recapture him or lose their jobs. (Source: frankly at MyDramaList)