Around two thousand years before the present story, the moon disappeared from the sky. The seas rose and became violently unstable.
Different peoples and faiths preserve different names for the same catastrophe and era. Two established names are the Moonless Sky and the Time of Aegir.
People believed Njord was punishing humanity and began sacrificing to the gods. The seas eventually calmed, but Roo remained isolated by dangerous waters for nearly two thousand years. The sea became broadly navigable again only around a century before the present story.
What remains unknown
Roo remembers that the moon disappeared. It does not possess a complete explanation for why. Varren preserves older records and traditions concerning the catastrophe, but those records do not make the full truth simple.