That old book we found behind the false wall in the library?

 I deny all knowledge of it.

But I notice, if I were to dream I turned the pages, how the words keep appearing. Then disappearing.

Now I'm sure I imagined a wand in there a few minutes ago.

 And that lion? I'm sure it wasn't there before.

But I've never seen nor handled such a book. If I were you, I'd say, it doesn't exist.

(And for that, blame Borges.)