Ninety years have passed since the Tunguska Event, the mid-air explosion of an asteroid or comet near the Podkamennaya Tunguska river in Russia. Ichirō Maeda, a graduate student of astronomy at the Kiso Observatory of the University of Tokyo, observes an object which he initially thinks is a new comet.

It is nothing of the kind. Instead, it turns out to be a massive alien starship decelerating toward the Earth. It crashes on Sakhalin Island, just days before Russia’s financial collapse. Humanity absorbs the shock of confirmation that aliens do exist and wage war in space, and sets out to study and rebuild the derelict ship, naming it after the mythical Cretan king Asterion.

But conflict soon erupts and escalates over ownership and control of what can be salvaged and understood from the hulking wreck.