Bree is an ordinary girl living in a Martian city where everyone dreams of going back to Earth. With her failing grades, she is amazed when she is chosen for a mission to Earth, a rare honour usually kept for the highest achieving pupils. Why her? But there are terrible shocks ahead. The Earth has been lost - the last war created ruthless genetic weapons that have overpowered their creators. Always under attack, in the ruins of Cardiff, amongst its wildlife, and at the Museum, Bree finds more and more proof that she can't trust anyone. When she starts getting strange messages from a voice only she can hear, whose side is she really on? Home or Earth?