Gareth: I’m scared.
Morgause: Do you trust me son?
Gareth: Yes – lets himself fall back and falls to the ground-
Morgause: Rule number one, do not trust anybody.
Morgause, also known as Morgawse, is a character in later Arthurian traditions.
Her character is fully developed in Thomas Malory’s compilation of Arthurian legends Le Morte d’Arthur, in which Morgause is one of three daughters born to Gorlois of Tintagel, Duke of Cornwall, and the Lady Igraine. According to Malory, her mother is widowed and then remarried to Uther Pendragon, giving birth to his son Arthur, and Morgause and her sisters, Elaine and Morgan "le Fay", are married off to allies or vassals of their stepfather. Morgause is wed to the Orcadian King Lot and bears him four sons, all of whom go on to serve Arthur as Knights of the Round Table: Gawain, one of his greatest knights; Agravain, a wretched and twisted traitor; Gaheris; and Gareth, a gentle and loving knight.
Years later, her spouse joins the failed rebellions against Arthur that follow in the wake of King Uther’s death and the subsequent coronation of his heir. Shortly after her husband’s defeat, Morgause visits the young King Arthur in his bedchamber, ignorant of their familial relationship, and they conceive Mordred. Her husband, who has unsuspectingly raised Mordred as his own son, is slain in battle by King Pellinore. Her sons depart their father’s court to take service at Camelot, where Gawain and Gaheris avenge Lot’s death by killing Pellinore, thereby launching a blood feud between the two families.
Nevertheless, Morgause has an affair with Sir Lamorak, a son of Pellinore and one of Arthur’s best knights. Her son Gaheris discovers them in flagrante and swiftly beheads Morgause in bed, but spares her unarmed lover.
Morgause is the Queen of Orkney, mother of Sir Mordred, with her half-brother King Arthur, and mother of Sir Gawaine with her husband, King Lot.
The Queen of Air and Darkness tilted back her head and laughed. A more ghastly sound I hope never to hear. ‘Do you think I care about these trifles?’ ‘Murder is no trifle, woman,’ Arthur said. ‘No? How many men have you killed, Great King? How many have you slain without cause? How many did you cut down that you might have spared? How many died because you in your battle-rage would not heed their pleas for mercy?’ The High King opened his mouth to speak, but could make no answer.
— Stephen R. Lawhead, Arthur (The Pendragon Cycle)
Arthurian Legends 