Winnie the Witch would like to announce that in this book she is actually Winnie the pirate and Wilbur is not her cat, he's her parrot. When they arrive at Cousin Cuthbert's party in their fancy dress, Winnie and Wilbur discover a whole crew of children, ready for action. With a map and a fine pirate ship (thanks to a little magic from Winnie) they set off to find their treasure island. But a band of fierce pirates is already there. What will Winnie and her fancy-dress pirates do? Will they manage to get the treasure? Join them in an adventure to remember on the high seas, it's pure swashbuckling magic!