Crowley's not quite close enough to reach over, which is a pity; after a moment, he pushes himself off his elbows and crawls forward to lie on his stomach instead, book propped open (with a certain amount of negligence) in front of him.

(This does put him near enough, but he doesn't reach out. Maybe that wasn't the point. Instead, the other hand holding down the fluttering pages, Crowley swirls his fingertips through the sand, drawing crumbling shapes, and getting it underneath his nails.)