Tan Jingtian, a graduate student of toxicological entomology at the Provincial Institute of Insects, was accidentally involved in a bizarre case. The cause of death was directly related to a rare insect, the bullet ant. In order to clear his name, Tan Jingtian assisted the police in solving the case, and thus came into contact with the young female forensic doctor Jin Ling. Tan Jingtian's attainments in the field of insects and Jin Ling's precise forensic analysis complement each other, and he worked with the criminal police captain Chen Han and other criminal police to track down the clues of each case. Tan Jingtian, Jin Ling and other criminal police officers worked together to solve the "American cockroach case", "micro-spined blind bug case", "kowtow bug case", "multi-eyed gray butterfly case", "spindle poisonous rove beetle case" and other cases. In the process, Tan Jingtian also solved the mystery of his own life experience and uncovered the real culprit who had been hiding for many years.