Life as a tank mechanic won't make you famous, but at least no one shoots at you.

That's what veteran maintainer Rande 'Vandal' VanDelle of the Chevaliers Private Calvary thought. Until, during a routine maintenance patrol, he found himself fighting for his life inside the company's oldest upright tank.

Bruised, battered, and barely standing, Vandal soon returns to the cockpit to bolster the ranks of a desperate defense force. As he and his fellow Chevaliers attempt to hold back the flood of turncoats, spearheaded by a legendary cadre of off-world mercenaries, Vandal must learn to master the fickle and deadly upright tanks if he wants to live to see the next contract.