The Wolf and the Crown by A.A. Attanasio
From the Goodreads website:
"The Warrior KingArthor, Eagle of Thor, must lead his people not only against their own ancient sorceries, but against the worldly empire that would make Britain's destiny a footnote to its own. Already rolling on the roads from Tintagel to Camelot is the great wheel that will become the Round Table.
But the perilous order promised by Arthor's victory is threatened by forces beyond human ken. For Merlin has descended into Hell, to fend with the Fire Lords who give the Universe its shimmering form. And for the young king himself, there is a sacred Grail, and an Earthly love, to seek....
The Wolf and the Crown
A. A. Attanasio's epic and lyrical retelling of humankind's most beloved legend weaves into one magnificent literary tapestry the hallowed warp of Arthurian lore, the shaggy woof of Druidic myth, and the shimmering strands of quantum science."
As usual, the more complicated the book, the more I seem to like it. This is the third book in the series and I loved it.