The Brightstorm twins are back for another adventure! Eudora Vane has organized an explorer fleet to search the Eastern Isles, the last known destination of missing adventurer Ermitage Wrigglesworth. Harriet Culpepper and the crew of the Aurora join the mission, but they don't believe that Eudora has good intentions. What is she really looking for? Arthur is determined to find out, and when disaster strikes and the Brightstorm twins are separated, will he and Maudie be able to find their way back to each other?