The unsolved case from six years ago has once again emerged from the concrete blocks at the bottom of the river to reveal the criminal's deepest fear - the "inner demon" Chen Yitao. In the spiritual world constructed through books, will Chen Yitao get lost again, or will he successfully solve the mystery? The ceremonial cement sealing case, the pursuit of the tired police officer, Chen Yitao's always invisible smile... Is the cat reading a book, or is there a cat written in the book? Is it an illusion caused by the churning of memories, or is it like a dream after the incident?
"I hope you don't know how terrible she is."