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.

Darkness steals into the very heart of Camelot, as Morgana and her puppet Queen hatch a sinister plan to murder the King. But when stable hand Tyr Seward becomes caught in the crossfire, he threatens to ruin everything… As the plot thickens and reaches its deadly climax, can a suspicious Merlin unravel the truth before it's too late?