Morgana was looking for the Diamair, the key to all knowledge, so that she could find out what Arthur's Bane was. With this information, she would have been able to find out how or who by, Arthur will die. Morgana didn't know that the Diamair was in fact the Euchdag, yet ordered the prisoners the Saxons captured, to dig in the mountain to find it. Gwaine saw a glowing in a cave and went to inspect. It was there he found the Euchdag, but was brutally beaten by the Saxons. As Gwaine was injured, the Euchdag found him and cured him of his wounds. When Gwaine woke up, she explained to him that her kind was shunned and hunted for hundreds of years and as a result she is the last one alive. When Arthur and Merlin arrived to rescue Gwaine, the Euchdag fled.