Cam and Jonesy battle their way through a Ringhead stronghold, trying to find their way back home. What they will find as they fight their way out will challenge everything they think they know about the Ringheads. On Earth, the tide of the war shifts as the alien xenoforming technology threatens to cover the planet in ice. Sasha, Mack and the Union Wolves battle the Ringheads and race to stay ahead as the aliens claim more territory each day...