Thomas Dane was on his way home when he was attacked out of nowhere in the park. When he wakes in hospital he realises with some confusion he can read his doctor's mind! By eavesdropping on his doctor's thoughts, he learns that someone else was attacked at the same time he was and that she was in hospital as well - a girl called Karina. Information is very slowly released to the two of them. They have been chosen. Whoever these people, or creatures, are, they are sending Tom and Karina on a journey - not through space but by vast stretches of time.