When Mark wakes one morning, he thinks the planet with the four suns is Earth - but he's not sure. He goes to the cinema and sees the film he watched last week - but his friends don't remember it at all. What's wrong with the day? What's wrong with Mark?

Having stopped taking his daily pill, Mark finds a host of memories return to him, intensifying his suspicions that the world he is living in is not his own - and isn't real. He learns that the aliens Osmids have swapped him, the real Mark, with a changeling. Just as this real Mark is in a false Brighton, there's another version of him in his real home. The Osmids' intentions are sinister, and they're not easily defeated. Can Mark imagine Brighton as it truly is and return home, or will the Osmid version last for ever?

This book is part of a book series called Hodder Silver .

There are 176 pages in this book. This book was published 2001 by Hachette Children's Group .

Since training as a dancer, Nell Coleman has led a fairly nomadic life - spent living in Scotland, England, Canada and the USA - and has pursued a number of careers. She now lists her occupations as writer, director, actress and costume maker (historical and theatrical). She has written plays for radio and the stage, and the lyrics for musicals. This is Nell Coleman's first published novel.