On a distant mining world gone dark, Captain Isabel Vega leads Helios Three, an elite marine unit, to find out why an entire colony has fallen silent. What they uncover is not rebellion nor a simple disaster, but a new kind of weapon, alive, adaptive, and disturbingly tied to their own chain of command. As the infection spreads through tunnels, machines, and minds, Vega must choose between following orders and saving the few survivors still clinging to life. Trapped between a mutating enemy below and political pressure from orbit above, she and her squad fight to keep the outbreak from reaching the wider galaxy, even if it means burning the world behind them.