Greg Paffen, a new super mutated in the last meteor shower, is murdered by the creatures - but finds his mind transferred into a robot. He seeks revenge as more attacks of the Hordes occur, and the Goth mutants as well as the heroes of Metrocity seek to find the cause behind the red brutes.
The prison system finds a place for Chrome, Diva meets her agent, a bridge is nearly destroyed and the Gahranii aliens continue their involvement in the city throughout the story.
The ongoing H.E.R.O. series continues in its fifth novel with H.E.R.O. - Horde. Heroes from the previous novels continue making appearances, including Psystar, Spartan, Black Tiger, Diva, Razorwing, Rayna and others.