The Crosstime Series

by Andre Norton

(aka) Blake Walker

 

Crossroads of Time, The ~ 1956;

When Blake walker foiled a murder attempt on one of his neighbors he somehow found himself drafted into a fantastic chase for a dangerous criminal – Through the almost infinite levels of alternate Earths.
It was a chase would take him through level upon level of unknown dangers in search of a ruthless genius who had found our Earth the perfect place to begin his series of conquests.
If Walker succeeded, he would save Earth. If he failed, his homeworld could be enslaved, and he could be trapped on an alien Earth!

 

Quest Crosstime ~ 1967 (aka) Crosstime Agent ~ 1975;

On an Earth exactly the similar to ours geographically, but in which events of history and society took strangely different turns, in a Quest Crosstime.
Born in the Earth we know, Blake had become a citizen of that alternate world thought himself trusted until the mysterious disappearance of his patron’s daughters, the rebellion of the time-travel engineers, and the outburst of  a plot to use the secret of time to loot a hundred unsuspecting worlds.
Blake’s search through alternate Earths’ his daring adventures with alien empires and hostile beings, all combine to make this one of Andre Norton’s most unusual and exciting novels.

 

Crosstime ~ 2008;

Omnibus featuring The Crossroads of Time and Quest Crosstime.