The Defiant Agents

The Defiant Agents is a science fiction story by Andre Norton. We learn of an encounter between Western heroes and Russian Communists, and a shadowy alien race that has used time travel to modify Earth. The alien library discovered in the previous novel (Galactic Derelict) proved to have locations of many unknown worlds. Finding the secure location of planet Topaz compromised, Apache operatives are sent on an emergency trip by Earth with a mind-altering machine. Once there, they encounter Russians similarly lacking in their memories. Will they successfully join forces and resolve matters?