And once again, Merlin and Gwen manage to trick the goblin by using poison, so it will vacate Gaius and they can trap it. When Gaius tells Arthur he is looking forward to seeing Merlin hang, the prince draws his sword to tackle it, but the creature escapes (yet again) by partially transforming Arthur into a donkey, which subsequently leads to another awkward moment between him and Gwen. Of course, Merlin escapes, and seeks Gwen’s help in putting a stop to the critter.

Uther immediately sentences Merlin to death and throws him in the dungeon. Not satisfied with this course of action, the goblin tells Uther that Merlin is responsible for the baldness, boils and flatulence. Firstly by telling the boy that if he wishes to destroy it, he’ll also run the risk of killing his friend, leaving Merlin well and truly stuck between a rock and a hard place. When Merlin realises Gaius’s body has been hijacked and reveals himself as a wizard, the goblin sneakily uses the situation to its advantage. What he is actually selling is a flatulence concoction, which leads to some awkward moments later on in the episode between Gwen and Arthur. Soon, Gaius is extorting gold out of the local villagers by claiming that a dreadful and debilitating plague is sweeping across Camelot, and that everyone will die an excruciatingly slow death.

Said shift includes going to a tavern, barking orders for his breakfast and putting the frighteners on the wicked Morgana by saying he can see into her heart and there is nothing but coldness there. Merlin doesn’t notice the complete shift in his mentor’s personality initially. Both Merlin and Gaius set a trap and manage to contain it in a room, only for it to morph into a small orb of light and possess Gaius.

Merlin season 3 episode 4 full episode