The Strange World of Mark and Anna

Mark arrives at a new school and meets Anna. They soon realise they are connected in some way and learn they have similar histories of being abandoned as babies and adopted. As they discovers strange powers in themselves they realise they are twins. They have both been left a gift of a maysterious box by an unknown grandmother. Then they learn that they are part of an alien species, abandoned on earth two centuries ago by an accident to a spaceship. Soon they embark on an extraordinary mission that takes all of those powers and their courage as they must save their own people and stop a long-running war between two groups.