From Astounding Tales Published February and March 1955

The Paratime Police had a real headache this time! Tracing one man in a population of millions is easy—compared to finding one gang hiding out on one of billions of probability lines!

This story from 1955 has rocket ships, time travel, slaves, post-hypnotic suggestions, drugged citizens, and a complete disregard for human rights. And those are the good guys. As a look back in time at "classic" science fiction, it's an interesting snapshot of a time when tobacco was common, sexism was unconscious, and female characters were a long way from Lara Croft.