C138 Mutual falling trap

Gan Yibo didn't answer my question, and before I could see where he had touched him, a secret door opened in front of us.

At first glance, there was nothing special about it. The three sides of the room were all closed-off, five-storey cabinets, and in the middle of the room was a bed similar to an operating table. I looked at the cabinets and thought, that's where the books are