Becky and Joe Mellor return to Bowen Hall for the half-term holidays to find thing are as unusual as ever. Of course, that's to be expected when you're sharing a stately home with a dinosaur, a winged horse, two sabre-toothed tigers and Bowen Hall's latest resident - a dodo named Deirdre. Things, however, get more intriguing when American time traveller, Bruce Westbrook, arrives with two gold doubloons that seem to possess strange, supernatural powers. So begins a thrilling adventure that leads Becky, Joe, Uncle Percy and Will to 1920s Chicago, Victorian Edinburgh and the 18th century Caribbean - battling gangsters, pirates, sea monsters and zombie sharks on a quest for the legendary Pandora's Box ...