The fifth seat by the window of Class 3, Grade 2, Nancheng No. 1 Middle School, which is hot in the midsummer, has been vacant for a long time, but the tabletop is clean every day. When the transfer student Shen Ci first came to register, he noticed that all the teachers, students and teachers in the class were evasive when talking about the vacant seat. The teacher from the Academic Affairs Office said "poor" unintentionally, which became the beginning of the story. The owner of the original seat, Zhou Yu, was deemed insane after her parents died in a gas accident and was recuperating behind closed doors. Rumor has it that she sneaked into the empty classroom every night, wiped the desks over and over, and always murmured to herself: Someone is crying in the wind. Shen Ci didn't believe the crazy rumors. He stayed at school late at night and bumped into Zhou Yu who was cleaning the table alone. He slowly dug deeper along the clues and accidentally discovered that there was a man-made conspiracy hidden in this seemingly unexpected gas tragedy. Zhou Yu pretended to be stupid to protect herself, secretly hid diaries, secretly collected evidence, and avoided the surveillance and persecution of her aunt Zhou Min and the school director Wang. With the help of secret letters, burnt pages, and secret recordings found between desks, Shen Ci joins hands with the trapped Zhou Yu, and uses an empty desk as a clue to unravel the murder case cloaked in an accident. In the hot summer, he seeks the truth for his family who died in vain, so that the empty seat No. 5 That has been left unoccupied all year round can finally be redressed.
