|summary=Mattie Butterfield and her family are going on holiday to Cornwall and as ever for Mattie there's lots for her to worry about. What if they lost one of them on the train to Cornwall? What if someone fell over the edge of the cliff? What if... As usual Mattie can think of all sorts of things which could go wrong and it looks as though her worst fears are going to be realised when the family manages to leave Jellico the dog on the station platform. It's a long journey to the south - eight hours on the train and then another hour on the bus to get them to the campsite, but after a couple of days they've all settled into a relaxed way of life. Mattie makes friends with a local boy too - although strangely enough no one else can see him.