With the future at stake, Douxie and Claire cling to the hope that Arthur and Morgana can reconcile. Meanwhile, humans are hunting trolls in the woods.

Merlin leads his ragtag crew on a quest to restore Excalibur and save Camelot. Elsewhere, Jim tries to convince Blinky that they're on the same side.

Morgana takes a new title — Mother of Monsters — and vows to usher in an age of reckoning. An epic battle begins in King Arthur's court.

Arthur seeks an alliance with the trolls of Dwoza as Gunmar begins building his army. Merlin and Douxie join forces to forge the amulet.

After returning to the 21st century, Jim makes a surprising sacrifice ... and a familiar face joins the fight. The Green Knight finally reveals himself.