Tear a page from the open book to give to Lorewalker Cho.
A ritual took place here, and from the looks of it wasn't successful.
Among the abandoned items a book lies open. The text on the pages is foreign to you.
Carrying the whole book may be difficult, but a single page might be enough. If you can get the page to Lorewalker Cho he may be able to tell you what it says.