Somehow enough people have survived the nuclear holocaust so that now, several centuries later, civilizations have struggled out of the darkness. As is common in science fiction scenarios, they are not the same civilizations as fought the "Doom War." (Tf only the Reagan administration leaders read a little more science fiction, then might understand this point, and act accordingly.) Societies are now centered in areas least devastated by bombs: the American West, New Zealand and parts of Europe farthest from the big cities. Place names and languages have evolved with the centuries. Some are easy to figure out, others take a little time. (I would have enjoyed having a world map included in the back) Understandably, most of the world considers nuclear weapons and nuclear power terrifyingly dangerous and any attempt to build or use either as aggression against all humanity.

Four civilizations stand out. The Mong are mostly great-grandchildren of Asians that migrated over a Bering Strait ice bridge to settle mid-North America. The Domain consists of remnants of European civilization held together and protected by Skyholm, a centuries-old warship/palace floating in the stratosphere. The northwest Union is a lodge-based anarchist society desiring technological advancement—particularly nuclear power. Dominating them all are the Maurai descendents of native New Zealanders, whose anti-technological viewpoint forces the Northwest Union to keep their nuclear-powered spaceship project secret. This project is the "Orion" of the book's title.

Anderson does a good job with all this complexity partly because he has, in various short stories over the years. worked out many of the details of these societies. In addition, his evolving ideas about the conflict between economic expansion and ecological balance allows him to examine sympathetically all sides of his characters' controversial debate. It is interesting to note that Anderson, by the evidence of those previously mentioned short stories (beginning with "Sky People" in 1959), believed the Maurai way to be the best. Now he is more critical of any plan to stop progress by force, and at the same time he demonstrates that nuclear power can be (if used in weapons) misused by the power hungry.

The author also does a brilliant Job of creating mythologies, religious and secular, for his characters and their civilizations. A continually soused troubadour, Plik, who almost by chance gets to know the main characters and participate in most of the action, warns them again and again that they are creating a new power myth (one that he very much fears and one they might not be able to control). But the myth evolves as the whole world realizes the necessity of freedom and the devastating consequences of the use of force.

The only problem with Anderson's novel is a stylistic one. I hadn't noticed this in Anderson's works before, but in Orion he too often uses long series of simple clauses for his descriptive imagery. Here are two examples

"In early spring, snow patched the brown ground, water gurgled and glimmered…cloud shadows scythed from horizon to horizon"

"The last snow melted, warmth and sunlight breathed a mist of green across the country, blossoming exploded, verdancy strengthened, the migratory birds began returning, plowman and plowhorse labored, rains blew gentle out of the west, larks jubilated while lambs and calves and winter-born infants lurched forth into amazement."