Tilda makes a promise to a fellow patient and sets out, aided by her dog, 'Dolph', to find one Arthur Miles Chandon, the patient's son, currently residing in the Holy Innocents Orphanage. They both escape the orphanage, but upon returning to the hospital, they find that Arthur's mother has died. Tilda and Arthur then head out on an quest to find a place called Holmness, encountering old friends, new friends and a few enemies along the way.