For the first time in over 300 the fires of Idirsholas burn years and Gaius is worried that a sorcerer has revived the deadly Knights of Medhir. Morgause returns and is determined to end Uther’s reign at Camelot.

In his determination to return magic to the kingdom and destroy Camelot, the ruthless warlock Alvarr doesn’t fear fighting Uther. However, he must first reclaim the Crystal of Neahtid, a precious magical relic of the Old Religion. Even though few can control its power, Alvarr believes that the young Druid Mordred can be an ally to use it in the benefit of their cause. Many have lost their lives trying to reclaim the crystal, safely locked up in Uther’s vaults. But Alvarr counts on Morgana’s powerful bond with the Druid boy as a secret weapon to undermine the king’s precautions. Despite Morgana’s fondness of Mordred, will she go as far as to turn into a thief and a traitor to help him and Alvarr? Merlin will be once more surprised by Morgana’s choices and the true power of the mysterious crystal.

Peace talks are held at Camelot when dignitaries from rival kingdoms arrive. King Alined is determined there will be no peace though and will use magic to make sure his wishes happen.

When Merlin discovers by chance a beautiful Druid girl called Freya trapped in a bounty hunter's cage, he feels like he has to do something about it and despite Gaius' advice not to get involved, he goes with his instincts and helps the girl escape. The young warlock can't think of a better place to harbour the girl than the tunnels beneath Camelot, but it would be a short remedy since the bounty hunter won't resign to lose his prize and will conduct a frantic search for her and a fierce magical beast has been reported to be on the loose. As Merlin's friendship with the Druid girl grows in intensity, it is tested to the limit by the adverse circumstances and the boy is forced to make a heartbreaking decision in his struggle to keep Freya safe..

After a mysterious warrior challenges Arthur to a duel, an unpredictable and devastating chain of events is set in motion as both the young prince and Merlin find themselves on a strange quest at the behest of Morgause. Through the beautiful lady, Arthur will find out a dark secret that could bring about the most terrible and unexpected consequences, the downfall of Camelot being among them....

In his determination to rule magic out of Camelot forever, Uther hires the services of Aredian, a terrifying witch hunter who is most feared due to the fact that he stops at nothing in the quest to uncover all and every kind of sorcery. Even though no one is under direct suspicion, several people in Camelot are afraid that the witch hunter could see straight through them: Morgana is worried that Uther might have her executed and Gaius is concerned for the fate of Merlin and his own, since caring for the young warlock is considered crime and treason. Will all three be able to escape a dreadful fate?