Morgana ends up discovering a powerful ally in the Southron warlord Helios and they come up with the perfect plan to bring Camelot to its knees. With Arthur preoccupied by the beautiful Princess Mithian, it ends up falling to an absent friend to raise the alarm.

In the inky depths of an ancient pool, three soothsayers cast a dark judgment upon the King of Camelot.

But despite Merlin’s warnings, headstrong Arthur refuses to take the words of the Disir seriously and their fury rains down on Camelot. Only the greatest sacrifice can appease them, and with the kingdom in jeopardy, is it one that Arthur is prepared to make?

Faced with the King’s uncertainty, Merlin has just one chance to save him from his destiny, but this decision comes at the highest price.

Merlin knows he must act fast before Morgana’s twisted control over Gwen gets further out of hand.

But only the most powerful magic can save the Queen and this will not be easy, even for Merlin. As the High Priestess tightens her grip on Camelot, one thing is clear - she will not give up her puppet without a fight.

Morgana leads a terrifying manhunt in pursuit of her old foe Alator of the Catha, for she knows without doubt that he can tell her exactly where to find Emrys. Merlin's life is in severe danger, so when the mysterious Finna offers to help him, is he right to trust her?