Summarising the plot of a complicated science fiction series can add to the pleasure of reading it. Publishing the summary might either increase others’ pleasure or encourage yet others to read the work for the first time.
Before the Bureaucratic State took over Earth and banned space travel, a few “spindizzy”-powered spaceships escaped from the Solar System. When antigravity was rediscovered, cities left and became “Okies” trading with the extrasolar colonists. Cities and colonials overthrew the Vegan Tyranny. One city, Interstellat Master Traders (IMT), sacked a colony and fled to the Greater Magellanic Cloud. Earth police regulated trade and reduced a human interstellar empire. New York, fleeing the police by crossing the Rift, a valley in the face of the galaxy, found a wild star with a colonised planet, He. Okies helped Hevians to move their planet across the Rift and out of the galaxy faster than light.
When the germanium-based interstellar currency collapsed, the cities marched on Earth and were suppressed by the police. A surviving Vegan orbital fort attacked Earth under cover of the march but was destroyed by a planet flown into its path by Amalfi, the Mayor of New York. Police pursued New York to the Greater Magellanic Cloud but Amalfi tricked them into destroying IMT, mistaking it for New York. Former Okies ruled the Cloud from New Earth while a nonhuman civilisation, the Web of Hercules, replaced Earthman rule in Arm II of the Milky Way. The Hevians visited the Andromeda galaxy but discovered, in intergalactic space, evidence of an imminent collision between this universe and its anti-matter counterpart.
Returning to the Milky Way in search of scientific help, the Hevians passed through the Greater Magellanic Cloud where they met their former Okie acquaintances who initially mistook the approaching dirigible planet for a nova. Hevians and New Earthmen flew He to the Metagalactic Centre where they survived the cosmic collision long enough to create new universes from their own bodies. The Web of Hercules, whose power was based on the control of anti-matter, failed to occupy the Metagalactic Centre but transmitted a historical record to at least one of the new universes.
It is an unacceptable coincidence that the only two races, Earthmen and Herculeans, able to reach the Metagalactic Centre in time to intervene in the cosmic collision originate from the same galaxy. The Okie film series, if it had been produced, would have been an opportunity to re-address this issue.
James Blish, Cities In Flight (London: Arrow Books, 1981).