Annie and I will try the other two doors, then. Annie - the billiards room door opens into a bookcase. Lithuania and I moved that, so it should be as accessible as it can.

I'll go back to the drawing room since I made a promise to Gundam about something, but the two of us can swap keys very easily. We'll come bother you in the secret passage if we run out.

...It's accessible from the wine cellar. [In case Annie didn't know.]