Which Way to the Future by Cressida Cowell

Planet Earth, in case you do not know it, is a small, green little world, out on the end of a remote and rarely visited Milky Way. All Magic was supposed to have disappeared from this particular planet many centuries earlier. But in an ordinary, slightly damp part of the planet there are five human children with extraordinary Magical Gifts that the universe has never seen before. Only two of them don't know it yet. What will Mabel and Izzabird's Gifts be? And how will they navigate Bounty Hunters, a witch and three perilous tasks to reach the end of their story?