Having had a narrow escape last week at the hands of the seemingly beautiful Princess Elena (who wasn’t so beautiful on the inside), Arthur now finds that Gwen holds his future in her hands…and she may be forced to make sure he has no future at all when her estranged brother Elyan (TV newcomer Adetomiwa Edun) needs her help.

Gwen has struggled to make her own way in life, with no mother to guide her and her father killed by King Uther. Gwen hates Uther for that but has said she would never kill him in revenge. Would she sacrifice the life of his son, Arthur – whom she loves in silence – to save her brother, though? That’s what she’s expected to do by Cenred (guest Tom Ellis)… Yes, that dastardly King has returned to wreak havoc in the Camelot kingdom and is again having his strings pulled by wicked witches Morgana and Morgause (guest star Emilia Fox).

It’s a nightmare… Gwen doesn’t want either man to die and works with Merlin to save both their lives. But they’re up against a sister act that thrives on bringing misery to Camelot. Merlin’s magic is powerful but will it be strong enough to defeat the evil sorcery of both Morgana and Morgause? Maybe someone else will stop them…