The Defiant Agents is a science fiction novel by American writer Andre Norton, the third book in her Time Traders series.

The Defiant Agents continues the series’ premise, an encounter between Western heroes, and the Russian Communists, and a mysterious alien race that has used time travel to alter Earth.

Kirkus Reviews comments, “Andre Norton, a polished writer of science fiction, weaves [her] outlandish fare in patterns intricate enough to attract the most devoted addict.

This is pure science fiction ...” The alien library discovered in the previous novel proved to have locations of many unknown worlds.

Finding the secure location of planet Topaz compromised, Apache operatives, including Travis Fox, are sent on an emergency trip with a mind-altering machine, Redax, which activates their ancestral memories.