This story happened since 1908 B.C. In Siam or Thailand there were a terrorist who would like to conquer the country , the government official who work in the ministry of Interior, he got trained in a military before and joined the ministry. He got 6 friends who specialized in different sciences :- the pharmacist, the engineer, the coffee shop owner and his younger brother, the lawyer and the pathfinder. These all people support the detective with what they are specialized in. Besides them , there are few more reputated in the history and play an important role in this story. They are friends of the detective. The atmosphere is retro.
In book 1 and 2 there is a villain called Red Bat , he lured people to get them as their partisan.How the story goes. But in book3-4 , the villain is Nok Sak Phee(the Screech Owl monster)