question about the book

did i miss something? I thought Tony Todd found the book inside the wall of her apartment. Why did they then need her to "check the hiding place" later? Did she get the book back at some point? Did Tony Todd pull out a different book?

for a while i just figured tony todd needed her to "make the book work" or some such - maybe the book wouldn't write itself outside of her presence. but it turns out she's still hiding the book somewhere? WTF?

thanks for any help.