Anna and Holly have spotted an advert in the paper for a Holy Moly Holiday - the intergalactic vacation of a lifetime. They simply CAN'T not go. But how will they get enough money? Simple- they'll become royal babysitters for a day. Unfortunately, the girls are in for a shock. Once King Steve and Queen Sheila have left, they discover there isn't just one prince to look after. There are six. And worse, the country's arch enemy, King Alas-poor-yorick of Daneland, has decided to stage an invasion. Will the girls be able to keep their royal charges safe and still go on their dream holiday?