The duel was with a single sword for each opponent. Arthur was disadvantaged due to a rib injury, which may or may not have been the reason for Helios's short-lived triumph of Arthur, although the outcome may have been the same if the injury had not occurred, as Helios had showed remarkable strength when entering Camelot the episode before. Helios managed to disarm Arthur's sword, and took him down to the ground with a punch to the face. He immediately proceeded onto stabbing Arthur in the heart to kill him, but this attempt was thwarted, and Helios was killed instead, from a surprise attack from behind by Isolde. This, unfortunately, resulted in Isolde's death, as Helios made one last blow from behind as he fell (The Sword in the Stone).