There's an ocean of fire around, just burn the nerd's book. Magic book or not it's magic fire of a higher grade. It'll burn just fine. That's the weakness of casters in most media. They have a casting focus. Break that and even a world class mage becomes no more than an over dressed civilian.
"Thanks Mr. Aide, bring a bunch of powerful people here, just like I wanted, to stop the outbre... I mean, me. Stop me. Totally said me there! Anyway, chop chop, you have an hour, tops"