The Boudicca revolt has been squelched, the tribes of the Iceni and the Trinovantes have been exterminated by the Roman Governor of Britannia, Suetonius. He has sworn his revenge on the remaining tribes for the Celtic insolence. Marius and Delia are now King and Queen of a broken Celtic tribe, and Marius has to use all his skill and cunning to help his hunted people as they flee before General Suetonius' sword.

Reluctantly donning the mask of the liberatio mysticus, the "phantom" that hides the scattered tribes, the couple recruits Marius' ex-Roman century and what few Celtic warriors that remain to face the deadly Roman machine. They struggle to keep their people together and prevent the rest of a nation from fading into history.

But they are threatened by secret plots, jealousy, and a new enemy that hammers a wedge between them, a wedge that even an unborn child may not be able to dislodge when Marius falls under the charms of Delia's sworn enemy.

Sacrifices will have to be made to save their people, to keep the nation together, to survive the Roman rage. In the end, it may be more than their love or their lives they lose.