Corwin has escaped the dungeons of Amber, where he was imprisoned by his hated brother Eric, who had seized the throne of Amber. All of Corwin's siblings believe that guns cannot function in Amber, as gunpowder is inert there. But Corwin has secret knowledge: in the shadow world of Avalon, where he once ruled, there exists a jeweler's rouge that will function in Amber as gunpowder should. Corwin plans to raise a legion of shadow soldiers, and arm them with automatic rifles from the shadow world Earth. While gathering these forces Corwin discovers a more sinister problem growing among the shadows. He meets Dara, a woman claiming to be his great-grandniece, and later discovers a threat to Amber: a black road which runs across universes from the Courts of Chaos to Amber. With his newly trained army, Corwin marches on Castle Amber only to find it already under siege. Eric is mortally wounded and passes the Jewel of Judgment to Corwin, making Corwin Regent. The immediate danger passes, but Dara threatens greater peril after walking the Pattern and revealing herself to be a creature of the Courts of Chaos, intent on destroying both Amber and the Shadows.