It occurs between books #2 (Red Fox) and #3 (Dead Sky Morning) and is the perfect primer for anyone interested in the EIT series.

    Is she their next target?Cassie sets out to uncover what is happening, only to learn that she is a member of an ancient bloodline that enables her to use the Spear of Destiny—a legendary object that can alter the future. Now running from a secret organization intent on killing those from her bloodline, Cassie must—with the help of some friends—decipher the clues that will lead her to the Spear.Christina Diaz Gonzalez has created a fast-paced thrill-ride of a book, rich with riddles and myth, that young readers will not want to put down.

    Callie Velasquez holds hands with her boyfriend Jeremy as they follow Callie's new BFFs Penelope and Lissa up the trail. The four friends are embarking on a camping trip -- a trip that immediately goes awry. They lose their way on the trail, and encounter a charismatic stranger with questionable motives. And when Callie stumbles upon a dead body, it becomes clear that the danger that lies in the woods is deadlier than she could have ever imagined. Tensions mount and friendships are tested as these teenagers try to survive the most sinister of circumstances.