I was going to have them immediately go for the book and the note on it, but then it occurred to me that people might not be so inclined to immediately grab a book with a note on it that just suddenly materialized in midair and fell to floor. One might think to themselves "maybe I should question this thing that has happened and approach with caution, if at all".
I mean, obviously, they're going to read that note, but I'm giving these two at least a little credit in the self preservation and common sense department, here.
Of course, if this were a horror comic, we'd all be screaming at the screen for them not to read the note, and then one of them would, and a demon would show up, or whoever read it would be possessed, or maybe that demon would show up AND possess them, or any number of horrible things. We know what genre story they're in, but they don't, so--
Wait, what genre is this? Comedy? Dramedy? Sci-fi comedy action adventure with a side of cheesecake? Okay, maybe I'm not entirely clear on what genre this is, but I know it's not horror, at least.