Is the Forbidden Zone an adaptation of a novel?

Yes. According to the synopsis of the TV series "Inquiry into the Forbidden Zone", we learned that it is adapted from Dongyue Buku's novel "The Forbidden Zone". It tells the story of anti-drug policeman Gan Tianlei who repeatedly cracks drug trafficking cases, and how he still works hard despite the dilemma of fighting wits and courage with drug dealers. Adaptation refers to creating an original work based on the original work by changing the expression form or purpose of the work.