By 2069, the United States is already at war with Canada and Mexico when a second crisis arrives from orbit. Alien pods impact across North America, each deploying metallic tentacles on contact — injecting a biological agent that converts humans and animals alike into biomechanical hybrid creatures bent on destroying whatever remains organic. Dr. Bowen, studying one of the pods, loses control of his specimen. His daughter Miranda is attacked. She survives but is infected, the alien material fusing with her biology into something new: Steel Harbinger, part human and part biomechanical alien. Miranda is now the most effective weapon available against the invasion. Her path runs through Kansas, Las Vegas, San Francisco, Houston, Cape Canaveral, Washington D.C., the Antarctic, an alien planetoid, and eventually the Moon — both a mission to stop the invasion and a personal reckoning with what she is becoming. Enemies she defeats can be consumed to replenish her strength.