nIts the February after Gaeas defeat, and mysterious incidents are wreaking havoc throughout Camp Jupiter. If the Romans dont figure out who--or what--is behind the episodes soon, the Twelfth Legion could implode. Suspicion falls on Claudia, the Fourth Cohorts newest probatio. After all, the mischief started shortly after she stumbled into camp. Plus, shes a daughter of Mercury, the god of thieves and tricksters. To find out whether shes guilty or innocent, readers can delve into the pages of Claudias personal journal. Through her eyewitness accounts, they will visit the crime scenes--a row of seats in the Coliseum, an underground aqueduct tunnel, the strange staircase at the back of the principia--and see the bizarre events unfold. Theyll be right alongside Claudia when she discovers a secret so ancient that not even the lares know about it . . . a secret that holds the key to Camp Jupiters safety.