Peter and Elise Andersen and their friend Henrik Melchior are worried when Henrik's mother and a family friend, Matthias Karlsson, fail to return from a short flight to Sweden. Has something happened to Matthias's plane? Then a mysterious caller informs Peter that Ruth Melchior and Matthias are being held by the Russian forces occupying the Danish island of Bornholm. The charge: spying! But the line goes dead before Peter can ask any questions. Frantic, Peter, Elise, and Henrik set sail for the island with Uncle Morten at the helm of the Anna Marie. But their arrival is met by secretive Russian soldiers who deny keeping any prisoners. How can Peter and the others persuade the Russians to release Mrs. Melchior and Matthias when the soldiers will not even admit they are there?
Used availability for Robert Elmer's Follow the Star
March 1997 : USA Paperback
January 2012 : USA, Canada, UK Kindle edition