The Lake in the Clouds — Edward Willett

Ariane is on her own and on the run. Rex Major has swayed her erstwhile best friend Wally to his side. And when she finally hears the faint call of the third Shard of Excalibur, it's on the other side of the world, in New Zealand! Wally, meanwhile, is discovering that life as Major's “guest” isn't all it promised, especially when he finds out Major's plans for Ariane's aunt. With Aunt Phyllis under threat, Ariane has no choice but to walk directly into Rex's trap -- and hope she can find a way to protect both the Shard and those she loves.