In the science fiction thriller Riastradh by T. J. Duran, David Collyer, an ordinary man, finds himself in extraordinary danger when he discovers a Celtic necklace that has the power to transport people back and forth through time-and drive them mad in the process But when David tries to return the necklace to its rightful owners, he finds himself trapped between certain death and the terrifying Riastradh. Can he survive? Beautifully written and packed with suspense, Riastradh is as provocative as it is entertaining.