The Crossroads of Time is a science-fiction novel written by Andre Norton and first published in 1956 by Ace Books as one of their double novels. The story takes its protagonist through several versions of Earth as it might have been if history had gone a little differently. --wikipedia
Everything gets a second chance. That's the shattering discover Blake Walker makes when he learns there are innumerable parallel worlds, on each of which history has taken a different alternative path.
1980, mass market paperback reprint edition (of a title first published in 1956), Ace, NY. 242 pages. Another science fiction novel by "a superb storyteller." The chase is on for a criminal genius.
When Blake Walker foiled a murder attempt on one of his neighbors he somehow found himself drafted into a frantic chase for a dangerous criminal - through the almost infinite levels of alternate Earths.
Vintage Science Fiction. "Everything gets a second chance! That's the shattering discovery Blake Walker made when he learned that there are innumerable parallel worlds - on each of which history has taken a different alternate path! CROSSROADS OF TIME is a brilliant science-fiction novel of how Blake crossed from Alternate Earth to Alternate Earth in a search for the means to save his own home world from disaster!"
Vintage Science Fiction. "Everything gets a second chance! That's the shattering discovery Blake Walker made when he learned that there are innumerable parallel worlds - on each of which history has taken a different alternate path! CROSSROADS OF TIME is a brilliant science-fiction novel of how Blake crossed from Alternate Earth to Alternate Earth in a search for the means to save his own home world from disaster!"