Crux Migrations

Crux scouts usually appear one or two months before the main horde. Their arrival serves as a warning sign that the larger migration is approaching.

The migrations recur every generation and can last from less than two lunes to more than three. Their length varies with Calandra's luck, and each passage decimates the continent's population before survivors can rebuild.

During a migration, kingdoms reinforce legions, recruit soldiers, mount catapults and large crossbows, and send civilians into migration chambers, tunnels, cellars, and other shelters. These measures are defensive and preservative rather than a way to defeat the crux.

Fortified cities and weapons can kill individual crux, but they cannot stop a full migration. The previous migration lasted nearly two months in Roslo, killed thousands, and overwhelmed even prepared city defenses.

Sheltering underground protects people from direct crux attack but creates its own dangers during prolonged confinement. Ransom's maternal relatives died of illness beneath their Perris home during the last migration, and Luella pursued strengthening experiments because she feared people would be endangered both by fighting crux and by spending weeks in shelters.

The warning pattern is not fully reliable after the Ellder attack. Ransom reports that the known scout is dead, that no other scouts have been reported, and that the creature may not have been a scout at all, leaving the timing and even the nature of the approaching migration uncertain.

The five kingdoms created the Shield of Sparrows to help them prepare for and survive the crux migration. Since the treaty began, the kingdoms have endured nine migrations.

A migration three generations earlier decimated Perris, Turah's former capital. Afterward, Turah moved its royal stronghold into the mountains.

The expected timetable collapses when the crux appears months earlier than predicted and Ellder is attacked while its defenses remain unfinished. The early arrival turns the migration from a future spring danger into an immediate evacuation crisis.

Roslo still bears visible scars from the last migration. On one street, most houses were ruined, one destroyed house was left uncleared after its resident lost her daughters and husband, and a neighbor's home took a year to rebuild.

Margot survived a past migration in Quentis by sheltering underground, where she became ill while sharing a chamber with a family and healers locked the door to contain the illness. After she and her mother were released, Quentis's streets were filled with rubble and ruined houses, and the aftermath exposed survivors to looting and lethal human violence.

The coming migration creates a narrow opportunity to reach Allesaria and obtain something that might stop the crux; an earlier-than-predicted migration could end that opportunity.

The approaching migration gives the Guardian a deadline for containing Lyssa. He fears that if the creatures become infected, they could spread the infection across Calandra in a week.

The coming migration gives Ransom and Odessa an urgent deadline for stopping Lyssa. They fear that infected crux would carry the disease through the migration and destroy Calandra, making the failure to contain the infection potentially irreversible before the horde arrives.

Calandra's recorded history is closely associated with the migrations. Caspia notes that the first migration occurred about three hundred summers ago and that most written history begins there, though she suspects the missing pre-migration record may have been erased rather than simply destroyed.

The magical glass orbits are suspected of being connected to the migrations, but the connection remains unresolved. Caspia hopes destroying the orbits could stop the migrations or keep them from killing so many people, while Odessa's father says the approaching migration made the hidden search for the orbits urgent.