Young Brendan lives in the Abbey of Kells, a remote medieval outpost under siege from raiding barbarians. One day a celebrated master illuminator arrives from foreign lands carrying an ancient but unfinished book, brimming with secret wisdom and powers. To help complete the magical book, Brendan has to overcome his deepest fears on a dangerous quest that takes him into the enchanted forest, where mythical creatures hide. It is here that he meets the fairy Aisling, a mysterious young wolf-girl, who helps him along the way. But with the barbarians closing in, will Brendan's determination and artistic vision illuminate the darkness and show that enlightenment is the best fortification against evil?