A Dreamcatcher Guide Part 3: Nightmare Era Explained

This is an accumulation of different theories that i’ve seen online, and my personal interpretation.

Nightmare Era: Chase Me  - Breaking Out

When the girls are at boarding school, Yoohyeon kills a cursed spider that Jiu found. The curse is then released and each of the girls become an embodiment of a different nightmare. Jiu is diokophobia (fear of being chased), Sua is merinthophobia (fear of having movements restricted), Siyeon is claustrophobia (Fear of small spaces), Handong is scopophobia (fear of being watched), Yoohyeon is mazeophobia  (fear of being lost), Gahyun is basophobia (fear of falling). Now supernatural beings, The girls are stuck in their old school. Decades later, their school has been converted into a hotel, and a nightmare hunter is sent to investigate the paranormal activity. After the girls mess with him, he formulates a plan to trap them using a book that can trap them into the Nightmare Realm. He successfully traps Sua and Gahyun. Later, he chases Siyeon and Yoohyeon through the forest. While he’s distracted, Dami, Handong, and Jiu search his room and find the book. They use witchcraft to burn the book, saving Sua and Gahyun, and trapping the nightmare hunter in a mirror. As they leave the hotel, Dami drops the book in the forest.

The girls attempt to start a new life as photographers. Years later, a supposed client, who turned out to be a spider queen, comes to take revenge on Yoohyeon for originally killing the spider. The girls attempt to save her with witchcraft, but to no avail. The girls eventually split up after failing to save Yoohyeon. Many years later they reunite with the objective of finally saving Yoohyeon from the Nightmare Realm after Jiu finds the nightmare book hidden underneath a city in some ruins. They use the book to send themselves into the Nightmare Realm. Each of the girls get trapped in a different nightmare, separated from one another. The girls are able to find each other by a metaphorical string that pulls them towards one another, and eventually escape (hopefully. We don’t actually see them escape).