The Lady of the Lake by Jean Menzies (paperback)

Sapphic Love and Forbidden Secrets in Camelot
 
Lady Viviane leaves the lakes of the far North for the splendour of Camelot to capture the heart and hand of the young prince, Arthur. But it is Arthur’s sister Morgan who captures Viviane’s eye. Fierce and headstrong, Morgan sees another path – one she and Viviane can carve for themselves in this world built for knights and kings.

But in this kingdom no one is as they seem. And when Arthur pulls the legendary sword from the stone, his closest allies will do all they can to tear Viviane and Morgan apart.
 
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'A fierce, luminous and captivating reimagining of Arthurian legend' - Bea Fitzgerald