Qwelby and Tulia are teenage aliens, growing up in a world and environment far removed from our own. When the twins interfere with a forbidden experiment, they find themselves transported to opposite ends of our Earth – Qwelby in Finland and Tulia in Africa. To survive, they must re-establish their telepathic connection, find each other, avoid capture, and return home. They say that their people arrived on Earth 75,000 years ago, were the cause of the development of the human race, and now need the help of those humans if their race is to survive.