Merlin, an immortal sorcerer, falls in love with a mortal woman named Nimue. The sorcerer thinks about marrying her, but realizes he'd have to watch her die because of his immortality. They decide to reforge the Holy Grail, using the Flame of Prometheus, into a sword to cut away his magic so that they can grow old together. The two of them travel to the Temple of Prometheus, where the flame is located. Unbeknownst to them, Vortigan, the man responsible for destroying Nimue's village, follows them. At the temple, Merlin transforms the Grail into a sword, Excalibur. Suddenly, Nimue spots Vortigan and she alerts Merlin to his presence.
Vortigan attempts to make Merlin forfeit the sword to him and takes Nimue hostage. She breaks free and tries to kill Vortigan, but he fatally stabs her instead. After she seemingly dies in his arms, Merlin confronts Vortigan, whose heart
is unexpectedly ripped out by Nimue. Only then, she reveals to Merlin that she drank from the Holy Grail when he wasn't watching, thereby making herself immortal too. He begs her not to crush the heart, as doing so will make her dark. Unable to shake her grudge, she pulverizes Vortigan's heart to ash, triggering a monstrous change in her physical appearance and making her the first Dark One
. Fearing Merlin will try to take her power, Nimue smashes the sword, severing the tip from the blade, and steals the last spark ember. Merlin later creates the Dark One Dagger
from the tip. ("Nimue")