Arthur Prescott is happiest when surrounded by the ancient manuscripts of the Barchester Cathedral library, nurturing his obsession with the Holy Grail and researching his perennially unfinished guidebook to the medieval cathedral. But when Bethany Davis arrives in Barchester to digitize the library's manuscripts, Arthur's tranquility is broken. Appalled by the threat of modern technology, he sets out to thwart Bethany, only to find in her a kindred spirit - and a fellow Grail fanatic. Bethany soon joins Arthur in a quest to find the lost Book of Ewolda. Arthur and Bethany peel back layers of history, and when the future of the cathedral itself is threatened, Arthur and Bethany's search takes on grave importance, leading to discoveries about the Grail and each other.