The Invisible Enemy Author:Marthe Jocelyn What do you do when your enemy turns invisible and only you know what's happened to her? That's the predicament Billie Stoner faces when her arch rival, Alyssa, steals Billie's backpack and accidentally uses the magic vanishing powder hidden inside. — Will Billie take pity on Alyssa and try to find a cure, or will she let Alyssa stay vanished for... more »ever? In this spirited sequel to The Invisible Day and The Invisible Harry, Billie discovers that an invisible enemy is much more trouble than a visible one!« less