The kingdom is on the brink of collapse, with Morgana poised to strike. As Lancelot races back to Camelot with the dying Merlin, Arthur must continue on his mission to vanquish the Dorocha without them. Though the Knights know their journey to the Isle of the Blessed is fraught with danger, none could anticipate the sacrifice Arthur intends to make there.

The mysterious Julius Borden arrives in Camelot with news of a magical secret that threatens to change the landscape of the kingdom forever. He has located the final part of the key to the tomb of Ashkanar, an ancient mausoleum which holds a very special treasure: the last remaining dragon's egg. Merlin is understandably drawn in by Borden's news, and promises to help him. But just who is the enigmatic stranger and, more importantly, what does he really want with the egg?