After Socorro, age twelve and Kristal, age fourteen, return from their adventures On Mystic Mountain, they find themselves suddenly transplanted to a Scottish island! The family has inherited Castle Rossmore, on a remote island far away from the life the kids are used to. Not knowing who gifted them with the property, the kids seek to uncover the answer as well as many other mysteries they find as they explore the massive 35-bedroom castle! They meet new friends and together they work to make a difference in the lives of the people around them and the many animals that inhabit the Island.

Although the Island is beautiful and intriguing, they soon learn that it has a dark side as poachers seek to capture and sell a very rare Snowy Owl! The kids work together to protect the wildlife on the island from the many perils that seek to destroy them.

Kristal and Socorro learn that they can share the faith they learned about On Mystic Mountain. Will they be able to help their friends? Hamish, age sixteen, and a native to the Island, as well as nine-year-old, Ailsa, the daughter of a staff member, partner with the kids to solve the mysteries and bring new life to the sleepy island. They not only find friendship but learn that life has an important spiritual component that is important to all.

Enjoy the beauty, freedom and intrigue as you visit Mystic Island. Laugh with the kids as they have many encounters with the puffins, owls, sea creatures and Highland Cows! It's not like any other island you'll ever visit!