Caitlin now, finally, has all four keys, but still, she must find her father. Her search takes her to Nazareth, to Capernaum, to Jerusalem, following a mystical trail of secrets and clues in the footsteps of Christ. It also takes her to the ancient Mount of Olives, to Aiden and his coven, and to more powerful secrets and relics than she's ever known. At every turn, her father is just a step away. But time is of the essence: Sam, turned to the dark side, has landed back in this time, too, and as he unites with Rexius, leader of the evil coven, they race to beat Caitlin to the Shield. Rexius will stop at nothing to destroy Caitlin and Caleb, and with Sam on his side, and a new army behind him, the odds are in his favor.