"Our Children’s Children" by Clifford Simak, summary

The plot revolves around the sudden chronological exodus of an entire civilization, fleeing biological extinction and using previous eras as its only source of salvation. The science fiction novel was published in 1973.

Breakthrough from the Future

A blackened passageway appears beneath the branches of an old oak tree in Virginia. Hundreds of strange-looking people emerge from it onto photographer Bentley Price’s lawn. The first to make contact are gray-haired Maynard Gale and his daughter, Alice. They plead for mercy and say they have arrived from the year 2498.

In Washington, the news caught government circles by surprise. White House Press Secretary Steve Wilson interrupted his personal plans and contacted the head of state. President Samuel Henderson immediately declared a partial military mobilization to accommodate the displaced people.

Portals are opening all over the planet. The influx rate is reaching a million people per hour. Refugees are pouring out onto the streets of Boston, Denver, Chicago, London, Moscow, and Minneapolis. Simultaneously, tons of wheat begin to rain down from spatial rifts over starving regions of Asia and Africa.

Gale meets with the cabinet. He explains that five hundred years from now, humanity has been attacked by aggressive carnivorous creatures. These creatures know no peace and are driven solely by the instinct to destroy. Two billion Earthlings have decided to evacuate back in time. The visitors don’t plan to remain in the twentieth century and aim to escape to the Miocene, twenty million years in the past.

The new passage requires colossal material resources. The guests hand over the equipment plans and ask for help with resources, and in case of a monster invasion, they advise stationing heavy artillery in front of the manholes.

The emergence of monsters and social division

The military deploys its crew right in a flowerbed in Virginia. Soon, the crowd of refugees in the tunnel is driven into a panicked retreat by their pursuers. Two ferocious, multi-legged creatures with poisonous spines and tentacles burst out of the hole.

The artillery fires point-blank. The shell’s explosion obliterates the passage and kills one monster, but the second destroys the soldiers and disappears into the forest undergrowth. Price manages to snap a photo before the predator flees.

Henderson delivers a late-night televised address. A state of emergency is declared across the country, with price, wage, and banking freezes.

One morning in the mountains of West Virginia, farmer Elmer Ellis encounters a brood of growing chickens in his chicken coop. Fighting them off with his rifle, he suffers severe lacerations.

Biologist Isaac Wolfe warns authorities about the enemy’s abnormally accelerated metabolism. The creatures are capable of laying fertilized eggs without a mate, and the young grow within literally 24 hours.

Society is rapidly polarizing. Preacher Jake Billings launches a crusade after learning of the aliens’ atheism. Young people stage demonstrations demanding they be sent back to the Miocene, away from civilization.

Political maneuvering and hidden costs

Industrialist Clinton Chapman, through Attorney General Reilly Douglas, is seeking an exclusive commercial license to operate the tunnels. The magnate hopes to organize tourist trips to bygone eras.

Gale hands Wilson a briefcase containing a trillion-dollar diamond to cover the world’s expenses. Steve hands the treasure over to the secret services for safekeeping.

Ambassador Fyodor Morozov visits the White House. The diplomat insists on deploying foreign troops to comb the forests, hinting at the threat of a nuclear strike if the request is refused.

Physicists Nicholas Hardwick and William Cummings reveal the secret of time travel to their colleagues at the Academy of Sciences. The technology is based on the properties of a neighboring universe, where the arrow of time is oriented backward.

Sandberg is amassing regular troops in the Appalachian Mountains. Army groups are reporting an inexplicable phenomenon: pursued monster hatchlings suddenly melt right in their crosshairs.

The solution to the phenomenon

Price finds Wilson and hands over the latest footage. On the high-speed film, a Cretaceous landscape with ferns and dinosaur figures clearly appears behind the vanishing creature.

The predators adopted the wave principle of portals at the genetic level. Sensing danger from a human armed with a firearm, they reflexively retreated even deeper into the past, to the giant reptiles.

Henderson reveals to Wilson a plan to counter the greedy lobby. Knowing that returning from the past is impossible due to the thermodynamics of the parallel world, the president allows Chapman to finance the construction at his own expense.

Assistant Judy returns to the reception area after a failed flight to Ohio. Steve meets her in a dimly lit office. The threat of invasion has been eliminated, and humanity faces the long task of resettling billions of descendants to the primeval prairies.