It all starts on the morning the letter D disappears from the language. First, it vanishes from her parents' conversation at breakfast, then from the road signs outside. Soon the local dentist and the neighbour's Dalmatian are missing, and even the Donkey Derby has been called off. Though she doesn't know why, Dhikilo is summoned to the home of her old history teacher Professor Dodderfield and his faithful Labrador, Nelly Robinson. And this is where our story really begins.