In a flashback, we learn how Merlin adopted Douxie and Archie by saving them from persecution in the streets of Camelot by Sir Galahad. In the present, Archie and Douxie, along with Claire and Steve mourn Merlin's death. To stop the Arcane Order- who have captured and enslaved Jim Lake-, Archie and Douxie visit Archie's father, a large dragon named Charlemagne the Devourer aka 'Charlie', to help translate Merlin's spellbook in order to determine the location of the Genesis seals. While Krel, Steve, and Toby keep watch over Nari, Claire enters the shadow realm to find Jim's soul.
Meanwhile, Morgana realizes that her interests are no longer aligned with the Arcane Order, and she must try to repair her relationship with Arthur; she leaves for the shadow realm to find her brother's soul and free him from Bellroc and Skrael's influence. Morgana and Claire help each other in the shadow realm, but neither are successful in saving Arthur or Jim's souls; Jim is literally being torn apart, and Arthur brought Morgana back from the dead so that she could see him and the Order kill Merlin. Nevertheless, Morgana is now on the side of the Trollhunters and Wizards of Arcadia.