When Merlin's sister turn up with a strange story and some undeniably creepy personality aspects, a mystery unfolds. When Arthur is poisoned, everyone's favourite almost-gang (they just need the sunglasses now) go on a mad adventure.
Seamus has lived life after life, and every time, an important place has burnt down, and months later, he dies. When the nightmares start, he knows it's coming soon. And he'll need all the help he can get.