It has been a short time since the children, Pedro Armaz and the others have returned from their harrowing trip to Planet Mars. They were lucky to survive this, as Yermin, with the host of the Martian kingdom, attempted to take control of the whole world- and they very nearly did. However, they made it and are now relaxing in Sorrento on a family holiday in order to regain their strength and perhaps their sanity. Pedro Armaz and his wife, together with Ronnie and his wife have joined the Carters for the holiday and all is going well until Ronnie drops his bombshell - he wants to return to Planet Mars in order to gain information for a book that he is writing. Pedro flatly refuses to go or in fact, to have anything to do with it. However, he relents and they set off on what they think will be an easy trip as all life has ceased to be since their last trip. This soon changes as they are faced with ferocious caterpillars - Lepidopterans - who attack them and do everything to end their lives. The race is one, once again The Wishing Book goes missing when one of the caterpillars attacks and carries off Pedro Armaz. Can they survive? Can they return to Planet Earth? This, the fourth in the Wishing Book series is the best yet and is guaranteed to have the reader glued to the pages with the hairs on the back of their neck raised.