In book two, the excitement and mystery continue as Timothy, his sister, Sarah, and their friend Jessica journey from America to Edinburgh, Scotland, where they seek the Four Treasures of Ireland, especially the Telling Stone. They must keep the treasures from falling into the hands of Balor, who can use them to deprive the world of good. The children pass through Time out of Time as they undertake their quest and encounter a number of mythic and folkloric characters, including the Tuatha D\u00e9 Danann, Gwydon, Cerridwyn, and others.

In this book, a code hidden in a map is the key to finding the Stone, and readers work alongside Timothy, Sarah, and Jessica to decode the message. Along with the code, the book includes a glossary of the many historical, literary, and folkloric references mentioned in both volumes.