While Caleb and Cornelia are still at odds over his decision to stay on Meridian, the Knights of Vengeance seek revenge against the betrayal of those who backstabbed their former master Phobos to unisciti the rebellion.
Caleb and Blunk attempt to sneak into the castello and free all the rebels captured in the Battle of Meridian Plains but Cedric's men chase them and Blunk is left behind.
The Guardians are stunned to learn that their math teacher Mrs. Rudolph is the Meridianite nanny who brought Elyon to Earth twelve years ago. She opened a portal with the foca, guarnizione Of Phobos. but Lost it during the escape.
Phobos sends shapeshifting monsters into Meridian to pose as and discredit the Guardians so Elyon will lose what little trust she has left in her friends.
When Caleb discovers that Blunk took the key he was suppose to leave behind in Meridian for Vathek, the girls return to Meridian to return the key before Cedric and Phobos discover Vathek is a spy for the rebel army.
