As darkness rises in Bleasoria and the White Queen's magical sword mysteriously disappears along with her dispatched troops, powerful swords begin appearing across the realm to chosen bearers. A boy in Isloya gains druidic powers guided by ancient spirits, a woman in Ayeon discovers a life-and-death blade to free her fellow slaves, a street thief acquires mind-reading abilities to rule the underground, and a young woman hatches a forbidden dragon egg that only royals should be able to control. These separate events are harbingers of imminent peril, and only when these sword-bearers unite will they have the power to stop the spreading darkness from consuming their world.

As the Shadow King threatens to cross from the shadow world into the realm of light, the human White Queen struggles to unite the dragons under her harsh rule. Though she rose from nothing to become their chosen leader, her methods of forcing dragon breeding and wielding the uniting dagger may not be enough to stop the approaching darkness. When some magical swords of power fall into the shadow realm, their return will bring the Shadow King with them—and the dragons will be this world's last defense, whether under the White Queen's flawed leadership or not.

As the Shadow King's influence spreads and darkness consumes entire cities, Queen Lelearlas descends into paranoid madness, wielding her dagger to deadly effect while suspecting even her closest allies of betrayal. When the sword-bearer Selena reluctantly challenges for the crown and other kingdoms fall to political upheaval, the fragile alliances between the courts crumble just as they're needed most. Meanwhile, Mandy faces the ultimate test to become the dragons' true guardian, enduring trials that will strip away everything she holds dear. With shadow-possessed armies rising, sword bearers turning against each other, and the balance of power shifting across all the realms, the final confrontation approaches—but even victory may come too late to stop the darkness from consuming their world.