Merlin has devised a test.
All of the petty kings have gathered in Londinium to see who will be the next High King. Arthur and his retinue travel to the city in secret, but they are not the only ones with an interest in the Sword in the Stone. Morgana, Arthur's half-sister and the renegade queen of Rheged, has journeyed there with her Saxon lover, and petty kings have come with no kind welcome for the young High King.
Arthur pulls the sword, but the kings will not accept him. He is given the temporary title of Dux Bellorum, and with Merlin at his side, he sets out to unite the tribes of Britannia as the Saxon threat grows more menacing on their eastern shore.
Some battles are easy.
Others are carried out in secret.
It is the secret battles that Arthur will need to fear.
"Arthur Rex: Ex Lapis" is the second installment of an epic retelling of the Arthurian legend.
You only think you know the story.