Thirteen-year-old Faith Clancy knows there is something mysterious happening at Hollow Hills Middle School, even before she walks through the doors on her first day. But as she begins her eighth grade year, Faith has no idea that something mysterious has been walking the halls of Hollow Hills since the beginning of time. Faith, whose parents have just divorced, is happy to be rid of the bullies that tormented her at her former school and begin a new chapter in her life. As she eases herself into a routine, Faith is soon recruited into the Hollow Hills Explorers club by her new friends, Dalton, Finn, and Oliver, who tell her their mission is to explore the unknown. One night while on a scientific adventure to observe the blue moon, the explorers unexpectedly encounter an apparition that apparently only Faith has the ability to see. As the group investigates the apparition's origins, Faith realizes the ghost has taken up residence in her school and dislikes bullies more than she does. In this young adult mystery, a teenage girl who relies on help from her new adventurous friends and a ghost to take on bullies soon discovers the true meaning of trust, friendship, and believing in herself.