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I read this book in the mid 80's, and what I remember of it, is that time travel has been discovered (invented if you will), but it only works one way. It's possible to send poeple back in time, but it's impossible to go forward. That which has been sent back can't even be brought to its original time again.

This would seem fairly useless, but for one thing, namely imprisonment. The main character is, as far as I can remember, the leader of a group of prisoners. They regularly search they're surroundings for time junk1, which is what they call stuff that was sent back during early stages of testing the time travel. I also distinctly fossils of trilobites being mentioned.

One day a man arrives on The Anvil1, which is what they call the device (platform, scaffold, or whatever) where new prisoners and supplies appear. He claims to be a prisoner, but for some reason the main character gets suspicious of this new man, and starts following him. And in the end it is revealed that this man is an agent of the government, and that they have discovered a way to go forward in time, and that it has been decided that they have all been pardoned, and that they are free to return home. However, the main character decides to stay and he is employed as a guide to time tourists.

1Time junk and anvil are direct translations from my native language to English, but it's perfectly possible that those are not the names used in an official English version.

marked as duplicate by user14111 story-identification Aug 18 '16 at 7:37

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • @user14111 After skimming through the Wikipedia entry on that book, I say you're absolutely right. Post it as an answer, and I'll accept it. – Duane Dibbley Aug 18 '16 at 7:06

Hawksbill Station (aka The Anvil of Time), a novel by Robert Silverberg, also the answer to this old question. (A shorter version was published as a novella with the same title, "Hawksbill Station", text available at escapepod.org.) Here is a plot summary from Wikipedia:

Hawksbill Station was a penal colony in the Precambrian era created by the United States government, using time travel as a means to exile rebels and political dissidents into the past. The colony houses only male exiles, who are sent there as a "humane" alternative to execution. The machine only works one way, leaving prisoners are marooned in the past.

The prison is in a barren coastal area prior to the development of the land. The novel focuses on the personal relationship of the main character, the de facto leader of the colony, and both his government torturer/prosecutor and Dr. Hawksbill, each of whom had been members of the dissidence movement. It also explores the picayune ideological differences among the prisoners, and the confused circumstances leading to the establishment of the authoritarian government.

The prisoners, all of them middle-aged or elderly, are surprised by the arrival via the time machine of a much younger prisoner. The newcomer, ostensibly an economist, is questioned about economic theory and political ideology, and his answers reveal his essential ignorance of either. His ignorance and youth cause the prisoners to wonder if he is fact a political prisoner or a common criminal exiled for a heinous crime.

When the newcomer arrives via the time machine a second time, it is revealed that he is a police officer of a new government which overthrew the authoritarian regime but was unrelated to the dissident movements of the exiles; upon the overthrow, the new government discovered both the existence of Hawksbill Station and the means to time travel from past to future, making it possible to retrieve prisoners from the colony. The newcomer has been sent to evaluate the prisoners and to recommend whether they are mentally stable for retrieval.

With return now possible, the leader of the exiles realizes that he is a time traveler of a different sort: the struggle against the authoritarian regime, his life's work, is over; his closest friends in the movement and his bitterest enemies, who left the movement to join the authoritarian government, are dead; and those who finally overthrow the government have little connection with or regard for his brand of dissent. He is now somewhat inclined to visit the newcomer's future, but staying at Hawksbill Station is now the only existence he knows.

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