Six centuries after the alien Curosa imparted the wisdom of their dying race to Adrian Sawyer and gave him three massive city-ships, two of those ships -- City of Diamond
and City of Opal
-- are locked in a battle for intergalactic political dominance. Now the Protector of Diamond
has chosen a protege, young Adrian Mercati, and told him the hiding place of the Sawyer Crown, an artifact that will give him and the Diamond
unassailable superiority over the Opal
. But spies are at work, and a desperate race to find the Crown begins. Yet what neither side can see is that finding it may prove their downfall.