A strange and deadly disease sweeps through the army post where Cuchillo is seeking refuge with his old friend, Hedges. As the mysterious fever reaches its pitch, a bloodthirsty band of Indians, deserters and half-breeds raid the fort before running back into the hills with two child hostages – and Hedges.

As the Apache and a patrol give chase, the disease follows. Death is everywhere – where will it strike next? Cuchillo knows he hasn’t much time. He doesn’t know about the ace the killers have up their sleeve...