The Misadventures of Myndil Plodostirr by Michelle Franklin

"Life happened to most people, but Myndil Plodostirr happened to everybody else." When the abbot of the newly made Rogha an dá Dhíogha abbey meets Myndil Plodostirr, an orphan who thinks God speaks to him, he quickly decides that a talkative young man like Myndil is best left to himself. In the hopes of ridding the abbey of Myndil's company forever, the abbot sends him out on an impossible mission: to make himself a missionary and unite all the surrounding kingdoms under the banner of one god. What begins as a jape ends in infamy as Myndil's cheerfulness and goodwill accidentally bring about the Great War of the Dark Age. Will Myndil heed the abbot's will and convert the warring kings, or will he listen to the mysterious voice that plagues him and cause chaos across the British Isles?