The TV series is based on the bestselling novel series written by author Ahmed Khaled Tawfik. The book series is a long-running series and there are 81 novels published. The series is about a hematologist named Refaat Ismail who started to experience paranormal events and has to confront things in his past and present life.
Depending on how season one perform, Netflix will have plans for many more season afterward. After all, they have load of source materials to adapt the TV series from.
Source material: yahoo.com