As the tyranids consume the planet of Vior'los and its enclaves, an inside threat emerges in the form of the scheming ethereal Aun'Va, and the fortress world is soon reduced to its last eight warriors. Among them is Torchstar, a young rebel in possession of battlesuits prised from Aun'Va's iron grip, and as unlikely allies are thrown together in the dwindling hope of victory, Farsight's ultimate test is still to come.