Try to steal the key from Headmistress Ward
From Create Your Own Story
You sneak into Headmistress Ward's room. The key is on the table. You grab the key and sneak over to the library. You notice the library is empty. The headmistress mustn't be as concerned about students sneaking in there as she is about them trying to escape the school. You reach the gate to the forbidden section and use the key to get through. Inside you find a safe.
