You can't take a closer look at the book.
The instruction manual said to put your eyes into the eye receptacle on the device and plug the cords into your eye sockets. The guy that sold it to you was awfully insistent on giving your eyes to the machine, said it leads to better experience. But now the only thing you can see is the contents of the book.
You remember that the book was green. Its size was average and it fit into the slot. There was nothing unusual or suspicious about it. It wasn't too heavy for its size, it didn't smell weird.
Well, nothing unusual other than it was being sold on the black market as a heretical artifact. You doubt the seller's honesty though. Can't completely trust everything on the black market.