Chris Grabenstein has successfully shifted from a career in advertising and the occasional stand-up gig to become a best-selling author of books for both adults and children, the latter of which have won the Agatha Award four times. The Buffalo, N.Y., native’s latest offering for youngsters is the just-published The Island of Dr. Libris, the wondrous tale of a boy who discovers that whenever he starts to read a book, its characters begin to appear in real life. The prolific Grabenstein, who has crafted more than two dozen books since 2005, reads from and discusses The Island of Dr. Libris at Joseph-Beth.