Spice and Wolf Volume 12 (manga)

Lawrence and Holo's long journey to Yoitsu is finally approaching its conclusion. Having arrived in the town of Lenos, they encounter a jolly bookseller named Le Roi--but is he truly the fool he seems? They're closer than ever to laying their hands on a forbidden tome whose contents threaten to transform Holo's homelands, but in the world of merchants, sometimes the only one you can trust is yourself...