Precious container

Exploration Stage: Hidden Row
From: Agent Jones
Description: You seem to have lost your mind, Detective, suspecting involvement with an evil cult. Then how about we make a deal? Bring me the container of my book that was confiscated when you were captured by the detectives. I will prove to you that it is not an item influenced by witchcraft.
Completed: You are a wonderful person! As you can see, there is nothing magical about this book container. Nevertheless, I am relieved that this book container, including the key, is safe. I'm sure the detectives would have a temper tantrum if they knew you returned this to me. What? He already knows? That's too bad. I was so happy that you and I could keep our little secret...