From the mighty Castle of Tintagel, King Arthur rules Britannia unchallenged, his power forged with the help of the mighty sword Excalibur once stolen from the Lady of the Lake. Arthur's supremacy, however, is threatened; the divination of the prophet-wanderer Merlin tells of a great tragedy that will befall the King, perhaps bringing the greatest unraveling of all.

The instrument of the King's great unmaking will be in the form of Mordred, born bastard and heathen of an incestuous coupling of the bloodlines pun-Dragon and the Fay, conceived in the brutal rape of Arthur's half-sister, Morgan LeFay. Fearing for her life, the pregnant Morgan escapes from Tintagel with Merlin, finding sanctity on the Isle of Glass where Mordred is safely born.

His aunt Morgause and great-aunt Viviane shelter Mordred, gathering around this great son of a King, casting their prayers to "the will of life," and offering up to him the blessings from the Great Lady of the Lake. As Mordred grows older, he learns the secrets of the earth and lakes and trains with Merlin in the Eastern Arts of necromancy and war.

He learns of the "elements," the energies of the forest, and the "magick" of the faerie realm, the invisible boundaries existing in the world "unseen by men." It is a bucolic and rustic life, but Mordred is different from the other boys: Viviane tells him he is like the "soldier-mages," those who love other men, "as some fear in this world who know not of such love."

One day, at the edge the desolate territory, Mordred spies a wild hermit swimming naked in the Lake of Glass. Viviane warns him to say away from this knight, swordsman and friend of Arthur - and the "greatest betrayer" of their people. But Mordred ignores her, and soon he is caught up in the alchemy of love, "a mingling of confusion with flesh and soul."

As he falls in love, Mordred is deceived into thinking he can live a life unaffected by the machinations of the outside world. His mother, Morgan, dreams of vengeance, remembering how she was once hunted like a dog by her half-brother who stole the sword and the thrones of the kingdoms from her.

However, it is her sister Morgause who secretly plots, fed-up with swallowing a life of servitude to King Lot and to her sons. Now full of merciless fury, she has captured the half-soul of her sister and is intent to do battle with a King who has been given Excalibur, the most sacred tool of the greatest of kings. As Mordred becomes a man, he must deal with his guilt at his crimes of passion and his longing for the world that had begun to remake itself around him.

Author Douglas Clegg beautifully skewers the Arthurian legends, weaving a compelling story, single-handedly reinventing Mordred's sexuality. He is no longer the betrayer of Arthur, the knight Lancelot, and Guinevere, Queen of the Britons; he is now the seductive and passionate hero, a lover of men given the almost insurmountable task of finding the cauldron of rebirth – the Grail.

This is a lawless, violent and random world, caught up in ancient superstitions, where the Kings and Druid priests remember the terrors of Roman captivity and call out for Merlin, hoping that the ancient mage might save them from devastation. Those who worship the heathen gods and Christendom forge an uneasy peace - most have gone underground seeking refuge in the ruins of abbeys, monasteries, nunneries and the derelict Roman villas.

Mordred and his ilk remain tied to the rituals of the sacred midsummer rites, of the men of the tribes and the old ways of his people. But eventually, Mordred must leave the safety of Isle of Glass, for his destiny is predetermined and he is set on an irrevocable path that will become his life.

In this first part of this adventure, our young and heroic prince achieves a type of erotic understanding, arriving from his breaking of the bonds of innocence. Yet as he saves a damsel in distress and witnesses his enemies gathering - in the form of a newly rejuvenated and vengeful Morgause - Mordred realizes that the debts of his life are only just beginning.

• Isis