[Loki turns away from the bookcase to take the book Billy is offering him.]

And do you think this one will provide you with knowledge you do not have already? It seems rather...simplistic.

[He turns the book around in his hands.]

Of course! It might be they hide a super secret awesome book of spells inside a seemingly harmless book like this one! It would be utterly dumb if they would let a super secret awesome book of spells sparkle like the chests of Midgardian vampires!