Forge of Heaven is the second of C.J. Cherryh’s "Gene Wars" books, a companion rather than a sequel to her Hammerfall. Set on and around the Marak’s World of the former novel, many of the characters remain the same. Marak’s World, former site of the planet shattering ondat attack, is recovering nicely, and the main cast of characters from Hammerfall is still around to watch that recovery. Marak Trin Tain and his wife, Hati, still roam the plains, once desert, now blooming scrub. With centuries between themselves and the cataclysm that changed their Marak’s World, Marak and his family have made piece with the voices in their heads, and learned to speak to their fellow immortals through the nanoceles that set them all apart from other residents of Marak’s World.
But there are new voices in Forge of Heaven. Far above Marak’s World, in a city-sized space station called Concord, human factions live in awkward peace with the ondat who caused the Hammerfall, an event now in the very distant past. The repair and evolution of Marak’s World is the cause of that peace, and observing its surface the most important job of the humans onboard. That crucial job falls to a handful of “taps” - people modified to be walking media centers, and to one Procyon Stafford in particular, Marak’s newest chosen observer. The constant oversight by and mental connection of the taps on Concord offer Marak and his people vital information on the planet’s changes, leading them away from danger or helping them adapt to a world changing on a scale faster than any geologist would predict. That same gathered information works as a peace offering to humanity’s old and very alien enemy, the ondat. The interlocking lives of observers and observed have maintained peace for two species and multiple political factions on board Concord for hundreds of years, and preserved Marak’s World from further attack. But the watchers of Concord Station are about to fall under observation themselves, by eyes less than benevolent, with intent far from peaceful.
A strong story on its own, Forge of Heaven in many ways feels like a mirror inversion of Hammerfall. Where Hammerfall focused on planet wide catastrophe from a very small and human viewpoint, Forge of Heaven focuses on the small dynamics of human interaction from the Marak’s World seeing eye of a space station’s official observer. The residents of Concord Station live in a luxury not available to even the upper class of Marak’s World and have intellectual knowledge of an entire planet. But they can never experience the feelings of natural wind or witness a genuine sunset, and the same organized government that keeps the climate controlled and the streets safe limits the freedom of station dwellers to an extent worldbound descendants of the Hammerfall would never choose. Cherryh draws the connections between worlds, explicit or unspoken, with a light stroke and creates the sense of a far more massive story than seen in the two current novels. At the same time, she focuses on the small worlds of her characters with the same attention they give to the surface of Marak’s World. It’s a balance that invites the reader to share a part of the life on Concord Station, to envy the drama of a rapidly changing planet, and to hope for more of the "Gene Wars" series soon.