The God Mars Book Eight: Better Angels - The God Mars, #8

The God Mars is a pulp-style science fiction series set in a rich world of varied cultures and colorful characters. The series plays out on a partially-terraformed Mars, a half-century after a man-made disaster cut thousands of colonists off from Earth, and the fear of a rampant nanotech plague discouraged rescue. Left to survive for generations with few resources, the various groups develop unique new cultures at different levels of technology, ranging from the primitive to the frighteningly advanced.
But all are now trapped in an escalating war between an oppressive Earth that's terrified of potentially infectious nanotechnology, and invincible superhumans who claim to have come from a nightmare future caused by that same technology. In Book Eight: Better Angels, Earth's orbital forces have been knocked out of the sky, and are now marooned on the surface of what they believe is a hostile and infected planet, all communications cut off.
A relief fleet is incoming, seven months out, but its cargo and intent are unknown. Meanwhile, the resurrected Terina and her symbiotic Companion have seized control of the terraforming Stations, have demanded the withdrawal of all Earth forces, and are proposing the unthinkable in a desperate attempt to protect all the peoples of Mars from another sterilizing Apocalypse. Can there be peace between the worlds in the face of unreasoning fear, or must there be obliteration?