We open in a sunny wood. a sneezy Merlin has been scaring off the animals Arthur is hunting, so it’s just as well they hear someone screaming, or the day will have been wasted.
On investigation, it turns out a village is about to burn a woman at the stake. She’s a sorceress, and they claim her magic has ruined their lives. Arthur demands she is freed, and they take her into the woods to tend to her wounds, although Merlin believes she will not survive the night.
She wakes up just long enough to give Arthur a gift – the horn of Cathbad, a magical device that can summon the spirits of the dead – and then dies.
Naturally Gauis has seen this horn before. It’s very powerful, and he urges caution. However, it’s the anniversary of Arthur’s coronation, and of course this calls to mind the death of his father. But… what if… could Arthur use the horn to speak to his dad again? Might that work? Best not tell anyone just yet. And hit Merlin with a spoon.
Arthur decides to take Merlin out for a ride to the great stones of Nematon, with the horn. It’s his only chance to speak to Uther again, and he wants to say a fonder farewell this time around. So, into the stone circle they go, and Arthur blows his horn.
He finds himself in a ghostly realm, and a figure joins him out of the white murk. It’s Uther! Time for a wonderful, touching reunio… oh. Uther appears to be a little grumpy. He does not approve of the decisions Arthur has made in the year since he became king. He’s allowed commoners to become knights, to question his decisions, and his people don’t fear him. And worst of all, he married a serving girl, rather than making an alliance with another king.
Uther’s judgement: Arthur has failed, but has time to make amends. It’s the worst family reunion ever.
Back in the mortal realm, a dazed Arthur returns to Merlin, and sets about questioning himself extensively. And that’s when the strange things start happening. Doors blow open, a chandelier falls on the round table, curious breezes run through the castle, Percival is attacked by a flying axe. It’s all very rum.
Merlin confides in Gaius, tells him everything he has seen. He believes he can sense a presence. Gaius explains that a person entering the spirit realm should never look back as they leave, or risk the spirit entering the mortal realm. Merlin takes this news to Arthur, who is sceptical and bullish, but clearly rattled because he did take that one last look.
Then Gwen receives a bit of a haunting: shutters rattle, something drags her down the corridor, and then a spear comes flying at her out of nowhere. Hiding in the kitchen, she’s suddenly attacked by pots and pans, and eventually knocked out by a jar, at which point the kitchen catches fire.
Thankfully Merlin is nearby and he helps her out. Arthur is still unwilling to believe it’s Uther’s work, but Merlin is adamant. Gaius begins to prepare a potion that will allow Arthur to see Uther in his spirit form and then force him back to the spirit realm using the horn, which only Arthur can do, as he blew it in the first place.
Arthur and Merlin take the potion, tentatively, and set of in search of Ghost Dad.
Merlin takes the opportunity to give Arthur a pep talk, to explain how much better a king he is than Uther, and that Camelot is a better place with him on the throne. Then the spooky noises begin. They split up. Merlin becomes trapped in the store room when all the barrels fall off the shelves, leaving Arthur locked in the throne room with his dad.
A family row ensues. Arthur stands his ground, refuses to lead as his father did, and receives a shield to the head for his trouble. As Uther approaches his prone son, Merlin intervenes, and reveals himself to be magical. Now it’s Merlin’s turn to stand in judgement over Uther, which only appears to make him even crosser.
Back in the corridors, Merlin goes looking for Uther’s ghost, and is pinned to a door by lances. Uther approaches with a sword, but just as he’s about to attack, Arthur arrives, blowing his horn and banishing him to the spirit realm. It’s over.
And then, with this exchange, everything is put back in its rightful place:
There, job done.