Ravine is a planet divided. After years of skirmishing between secessionist and loyalist forces, the spectre of a bloody planet-wide civil war is now all too real. As tensions between the factions boil over into full blown conflict, Darien, Amber and the operatives of Hammerhead Squad are drafted in to help colonial forces restore order. Called back from suspension, Darien is forced to confront a past he tried to leave behind, while Amber finds her principles being put to the ultimate test. The operatives are hurled into a confrontation unlike any they've ever experienced, one that ensures their lives, and the entirety of human civilisation will never be the same again.