Maden, 17 years old. Summer holidays on the island. She is waiting for the mail. Between her room and the beach, between her father and cousins, the house, and, very close, the prison.

八个城中专业人士，一天醒来，赫然发现身处一个神秘密室，无人知道这是何等地方，眼前的只是一班完全不相识的人。密室是四方体的，上下左右前后都有一道门，可以通往隔邻的另一密室，但总是逃不过每个密室的特设机关，他们开始相信自己会…