Final Fantasy Crystal Chronicles: Echoes of Time on Nintendo DS - Need Help!!

I'm done with saving the little girl, I'm at the library and the southwest door is open. I've killed the guy there and this thing showed up west in the room. I picked up the book and layed it on the marble. Nothing happend. Just this sirkle following me, nothing more. Then I tried to hit the thing and it was... hittable. Anyway, I tried that thogether with laying the book on the marble, but this didn't work either. And now I'm stuck.

I can understand a part of it is my fault, for choosing Very-Hard. But still I'd be glad to find out what happend here. So if you have an idea, please inform me! Thank you! ^__^