Before she became Valkyrie Cain, teenager Stephanie Edgely thought her life in Dublin was mundane. Now the protégé and partner of skeleton detective Skulduggery Pleasant is poised to help save the world. Life is no longer boring, but it is downright dangerous at times. As she continues to learn elemental magic, Valkyrie is helping Skulduggery investigate the serial murder of Teleporters, whose talents are suddenly garnering a lot of attention from forces that are anything but kind. Meanwhile, teenager Stephanie Edgely is going about life in the everyday world. When Valkyrie’s mirror double experiences Stephanie’s first kiss, Valkyrie finds her feelings about compromising her life in one world to wield magic in another becoming more complex. Derek Landy’s third book in this entertaining series has the excitement and humor readers have come to expect (the banter between Valkyrie and Skulduggery is a particular delight) while continuing to develop its intriguing storyline, which ends in this volume with a shocking development. (Ages 10–13)