The Pirates Coin is a 3rd book in a series. It is about a girl and a boy who have shrinking magic. They can travel in time by going through doors in small rooms in a museum. Their names are Jack and Ruthie. When they Visit Jack's great,great,great... Grandfather,Jack starts to disappear! Now its up to Ruthie to bring Jack back! Can she save him? If want to find out read,The Pirates Coin!