Who took my charms textbook?

[alt_percy]

I missed it this morning. Oliver said I must have left it in the library, but I knew I hadn't. I distinctly remember putting it in my book bag in the common room last night when I was done revising, but it wasn't there this morning. I left the bag there in the common room when I was doing my prefect rounds.

Did someone borrow it without asking? I would like it back. Immediately, if you please.