Episode Name: Aithusa
Air date: 10/22/2011
Summary: A mysterious man by the name Julius Borden arrives in Camelot with news about a secret of magical nature which threatens to change the kingdom for ever: he knows the location of the last part of the key to the tomb of Ashkanar. The ancient mausoleum holds a very special treasure: the last remaining dragon’s egg. Merlin is immediately drawn in by Borden’s words and promises to help in the quest. But who is this enigmatic stranger and, more importantly, why does he really want the egg?      

Watch or download Merlin – Season 4 Episode 4 – Aithusa at below links.