Synopsis
The United States and several other countries were able to construct and launch space Arks before the Earth was destroyed by a collision with Bronson Alpha, a rogue planet that had entered the solar system months earlier. A French ship malfunctioned shortly after liftoff and crashed. Both American ships survived the voyage to the companion body, Bronson Beta, though they were separated and each unaware of any other successful arrivals. The two American ships' personnel are finally reunited nearly half way into the book. Bronson Alpha destroys Earth and moves out into deep space again, while Bronson Beta swings into what seems to be a stable, but eccentric, orbit around the sun.
Early in the story, the survivors of Hendron's own smaller Ark took stock of their situation and set out to establish a colony, already aware of the hint of a previous civilization: a road. Tony Drake and another associate scout out for suitable farmland, which is put to use, but during their return journey following the alien road, the two men come across a vehicle. After a mysterious disease passes through the camp, killing two colonists, Hendron forbids exploration, but some of the colonists defy him and strike out, bringing back wood from a distant forest. That night, an aircraft passes near the camp, beating a hasty retreat when it notices the campfire of wood.
Tony's former manservant, Kyto, explains he found a piece of paper blowing in the wind, and it reveals that a group arrived from Earth that intended to establish a "soviet", and they were made up of Germans, Russians and Japanese.
At Hendron's order, an exploratory aircraft is built from remnants of the Ark and its rockets, and Tony Drake sets off with writer Eliot James. They follow the road and discover a domed city. These are the remains of a native civilization, whose builders were essentially humanoid and had considerably higher technology than humanity (but this did not enable them to survive the freezing of their world).
They explore it for three days and then fly south and discover a search light beaming up in the dark. They discover it to be the second Ark from Hendron's encampment on Earth that had a disastrous landing, but they make a joyous reunion with its commander, Dave Ransdell. Ransdell's camp also saw a mysterious aircraft, long enough to see it had "lark's wings".
Tony and Ransdell fly back to Hendron's camp, finding that Hendron is visibly deteriorating in health and mind. Tony is jealous that Ransdell apparently will become the new leader also have Eve, Hendron's daughter, as his wife. Eve, acting as Hendron's regent, dispatches Tony to the Ransdell camp to deliver a radio, and the first signal received is that the Hendron camp has suffered some sort of attack. Tony and one of Ransdell's men return to the Hendron camp to investigate: everyone is lying on the ground.
They discover everyone is alive, after all, but drugged; they give the doctor antidotes and then hear an aircraft approaching. Assuming a "dead" sprawl, they watch the aircraft pass over: the men inside have Slavic features and have evidently begun a takeover attempt. The aircraft leaves, the doctor responds to the antidotes, and Tony prepares the weapon emplacements (rocket tubes from the Ark) to defend. An armada arrives soon afterward and is totally obliterated by the Hendron camp's weapons. The people gradually wake up; the other camp reports they are all right. Hendron hands command to Tony, and Ransdell is relieved by that choice. Tony decides to occupy one of the alien cities, not the one they found but a different one shown on a diagram to exist close by; they follow the road there.
During the trip, they encounter an alien automobile driven by a British woman; she explains that a British ship also made it over from Earth but landed in a lake; they were found the next day by the "Dominion of Asian Realists" group, which Hendron nicknamed "Midianites", and enslaved. The Midianites' society is like an ant farm, the colony being all important and the people nothing, but the top rulers live luxuriously.
The alien city is occupied and the tractors leave at once for Ransdell's camp to bring its people to the city, which Tony names Hendron, because Hendron died just as the convoy came into view of the city. Hendron is buried the next day. The scientists manage, with the Briton's help, to figure out how to charge batteries and operate machinery, and they also find hangars of the lark aircraft; some are armed and used for air defence.
Meanwhile, the planet is approaching aphelion, and nobody is entirely certain that the planet is in a stable orbit around the sun. The weather is getting colder, and one night, the Midianites disconnect the power supply to the city of Hendron's people. One member of Hendron's group seems to defect to the Midianites, while four others land in a city on the other side of the Midianites' city, and attempt to reach the Midianite city by an underground service tunnel's high-speed car. They are unsuccessful, but the female defector kills the Midianite leader, defeats his key people, and allows the British to take control. In short order, the story ends quite abruptly.
The Dominion is defeated, and the victorious American/British coalition settles into the domed cities, discussing a form of government that the former Midianites now seem resigned to living under. While challenges still exist, their immediate needs for shelter, energy, and food are taken care of. The story ends on an optimistic note with a reference to the first pregnancy among the colonists, Eve's and Tony's, and the confirmation that they have passed aphelion and are now definitely locked into orbit around the old Earth's sun.
Read more about this topic: After Worlds Collide