The history of how the world inside Holden Radcliffe's cyber prison existed with HYDRA in charge. It's not pretty. Inhumans live in constant fear of being found, and hydra takes pleasure in beating the shit out of them. Also, the sadistic Doctor Leopold Fitz is torturing inhumans for no apparent reason. Witness the world under the rule of the dictatorship. If u haven't seen AoS season 4, you may not understand this story.