The writing process of the series took place in the writer's room format in which the writers come together intensively for the creation and development of scripts. According to Carolina Kotscho, they had considerable freedom in writing: "we wrote without any limit. We imagined that eventually this limit would come, but it didn't. This was a grateful surprise!" The creator and director José Alvarenga defined the series as a crossing of various genres; ranging from police thriller, horror, terror and suspense to romance. The series was inspired by the first season of
True Detective, as well as other similar themed shows such as
The Walking Dead,
American Horror Story,
Supernatural,
The Hunger Games and
Lost. The fictional 800 m2 prison set, built in
Estúdios Globo, was inspired from
Alcatraz Prison. Denisson Ramalho, a writer who specialises in horror movies, had said that "it is the most 'from hell' Brazilian TV series of all time". == Release ==