Philip Reeve 
Here Lies Arthur 

Welcome to the dark side of Camelot. The acclaimed author of Mortal Engines delivers a "powerfully inventive" re-creation of the King Arthur tale (Booklist, starred review).Gwynna is just a girl who is forced to run when her village is attacked and burns to the ground. To her horror, she is discovered, but it is Myrddin the bard, a traveler and spinner of tales, who has found her. He agrees to protect Gwynna if she will agree to be bound in service to him. Gwynna is frightened but intrigued, for this Myrddin serves the young, rough, and powerful Arthur. In the course of their travels, Myrddin transforms Gwynna into the mysterious Lady of the Lake, a boy warrior, and a spy. It is part of a plot to transform Arthur from the leader of a ragtag war-band into King Arthur, the greatest hero of all time. If Gwynna and Myrrdin’s trickery is discovered, what will become of Gwynna? Worse, what will become of Arthur? Only the endless battling, the mighty belief of men, and the sheer cunning of one remarkable girl will tell."Nodding to canon and history while not particularly following either Reeve, like Myrddin, turns hallowed myth and supple prose to political purposes, neatly skewering the modern-day cult of spin and the age-old trickery behind it. Smart teens will love this." -Publishers Weekly (starred review)"Is there room for yet another reworking of the Arthur legend? If it’s this one, yes . . . Absorbing, thought-provoking and unexpectedly timely." -Kirkus Reviews (starred review) "A multilayered tour de force for mature young readers." -School Library Journal