Spellbound by Anna Dale
When Athene finally discovers a way to get rid of the bane of her life, her younger brother Zach, it is all made so simple for her. She meets the Gloam who casts a spell on everyone who knew Zach so that they forget all about him. But it is Athene who can't forget Zach and soon she is drawn into an incredible world of dark magic, underground kingdoms and twisted histories in her attempt to save her brother.