Jack Finney's Time and Again is a science fiction novel originally published in 1970. The book's protagonist, Simon Morley, is invited to be part of a "top secret" government experiment. He cannot be told what the experiment entails unless he agrees to partake in it, but agreeing to the experiment means giving up his present job, home, life, etc, for an indefinite amount of time.
Simon agrees to be part of the experiment, which turns out to be time travel. The first part of the project involves being immersed in the culture of the time "Si" is going to visit. He needs to be aware of what exists in this time and what doesn't, what types of clothes people wore, what books and newspapers they read, etc. Once he has completed this phase then he is ready for actual transport to New York City in 1882.
I have to admit up front on this review that I have never been a fan of fantasy fiction. In many ways you can call me a "doubting Thomas" because I have problems with plots that expect you to just "believe." I tend to be very logical and scientific in my thinking, so I require rational explanation in order to "buy in" to the concept of time travel. Time and Again's plot, however, requires the reader to just "believe."
Simon's character is directed to "observe, don't interfere" when he travels back in time. And he regularly reminds himself of this, yet so many of his actions I would classify as "interference" and I couldn't understand how he felt he was justifying his behaviors.
And at one point in the novel, the scientists indicate that another participant's time travel resulted in a man not being born. However, they felt this was inconsequential as the man was inconsequential. I found that extremely bothersome. I was also a bit doubtful about their approach to confirming that the time travel trips didn't alter history, but again, the novel is expecting the reader to simply "believe."
I did find Finney's treatment of the scientist group very interesting. They initially start out with the goal of just observing. But as they achieve success with each trip, they want to push the envelope to see how far they can go with the experiment. And this of course calls into question ethical boundaries.
Simon is a likable character, and the plot includes a minor mystery that Simon finds himself wrapped up in during his trips to 1882. And the element I enjoyed the most about the novel was its historical look at New York City in 1882. The book is definitely not without merit. But for this "doubting Thomas" there was too much I just had to "believe" and too much I questioned to make it a real winner.