Centuries have passed since insects descended on earth, eradicating other species. The Hive Monoliths, the ancient insect lords, rule over this world.

Sely, a girl with insect sap in her veins, seeks out her father to tell him about the sighting of a flying city.

Legend of ancient human civilization, the sighting of a flying city is a harbinger of misfortune.

But Sely isn't the only one who knows, and someone wants to prevent the news of the sighting from spreading. In misfortune, there are always those who see nefarious opportunities...

The murder of Sely's father is only the first event of an adventure into the depths of the swarm.