Short story on time travel where, at the end, a primitive follows them back to the present but gets scared of a delivery truck and jumps back through the device.
3Hi, welcome to SF&F. You should check out the suggestions to see if you remember any details to edit into the question. When did you read it? Where?– DavidWJun 15, 2019 at 19:11
1This is very terse indeed. Fleshing it out would dramatically improve it. How, for example, did they travel in time? How did the Primitive return? What was the nature of the "device"? Were there any time travel rules?– ValorumJun 15, 2019 at 20:38
possibly the same as scifi.stackexchange.com/questions/166298/…– OtisJun 19, 2019 at 15:17
Tunnel Through Time by Lester Del Rey
Two scientists create a time machine, looks like a metal ring standing on edge like a Stargate. In operation it looks like it is a circular rainbow. One scientist tries it, but fails to return. Each scientist has a son who is a teenager, both beg the remaining scientist to let them go back in time to rescue the lost scientist.
They find the scientist back in dinosaur times. Unfortunately a brontosaurus trips over the rainbow ring and causes damage. The scientist in the present sends a letter back through time saying the time machine was damaged, they are frantically repairing it, and they will have to bring everybody back to the present in million-year stages. They can't bring them home in one big jump.
At the next to last time jump, they are in caveman era. They are befriended by a local tribe, particularly by a little caveman girl. When they make the jump to the present, they discover that the girl followed them through the rainbow ring. They take her outside to go to one of the houses, but a delivery truck with its light on scares the girl. She runs back inside, where the scientists are testing the time machine, dives through the rainbow ring, and is returned to her home time.
Interesting.. I wonder if there are alternative versions with different endings -- I remember her being scared, and huddling in a corner, and the book ending with the hero wondering how she would handle the world..– K-H-WJun 15, 2019 at 22:09
1When the caveman girl lands in the lab, she huddles in the corner because everything is utterly alien to her. The protagonist leads her outside hoping to see trees and natural things. Unfortunately a delivery truck drives by. Jun 15, 2019 at 22:28
Ahh.. It was the early 80s when I read it; I must have just forgotten that part. Or, given the library I was at, it's possible the last page was missing :/– K-H-WJun 15, 2019 at 22:44
1I have this book, searched for because I loved it so much when I was 12. There are no alternate versions or endings. As a commenter mentioned, she did huddle, but also ran back through the ring, the only familiar thing, when the truck scared her. They are not mutually exclusive. The modern people were too practical to think she could make it there, unlike Asmiov's The Ugly Little Boy.. . The modern people were afraid that she would land in the middle of the tribal war they had run from, but Doc Tome explained that there would be a few hundred feet (or thereabouts) displacement. Jun 18, 2019 at 18:35