Roman scout Silus is deep behind enemy lines in Caledonia. While spying on a raiding party, everything goes wrong, and he must run for his life...with the head of the enemy leader in his hands. Little does he know the price he will pay. As Silus is inducted into the Arcani, an elite faction of assassins and spies, he must return to Caledonia, back into the wilderness, and risk everything in the service of his Caesar. Failure is not an option