One thousand years ago: An Icelandic warrior returns from battle, bearing a ring cut from the right hand of his foe. Seventy years ago: An Oxford professor, working from a secret source, creates the 20th century’s most pervasive legend. The professor’s name? John Ronald Reuel Tolkien. Six hours ago: An expert on Old Icelandic literature, Agnar Haraldsson, is murdered. Everything is connected, but to discover how, Detective Magnus Jonson must venture where the shadows lie…