Susumu doesn't trust the military because his sister died in their service, and the Argevollen is the only thing that might let him find out why. That machine doesn't obey orders the way a normal mecha should, it bends to his will in ways that terrify command and demand answers he's not ready for. A kid chasing his sister's ghost, one unauthorized sortie at a time, discovers that the real war isn't between nations.
Susumu Tokimune joins the Arandas military with a secret aim: to learn the truth behind the mysterious death of his sister, who died while serving. The Kingdom of Arandas and Ingelmia have been locked in a long war, stalled at the fortress of the Great Wall until its gate finally opens. When a civilian convoy comes under threat and his own battle mech is destroyed, Susumu breaks ranks and climbs into the cockpit of the Argevollen, an experimental silver machine. Once activated, it conforms to his mind alone. Thrust onto the front lines of a punishing war, his one sure ally is a civilian contractor whose reasons for being there are as tangled as his own. His chance encounter with engineer Jamie Hazaford and the Argevollen is set to shape the fate of his Independent 8th platoon and the course of the war in this action mecha series.