Keith Laumer 
Dinosaur Beach 

Appearing from the remote future, Nexx Central agent Ravel is emplaced in America, circa 1936. His mission: to undo successive tamperings of the time stream which threaten the survival of Mankind. He falls in love with a lovely, simple girl, Lisa, but in the midst of his happiness is called away to Dinosaur Beach.Dinosaur Beach is a Nexx Central station located millions of years in the past, in the Jurassic Age. But shortly after Ravel’s arrival, the station is attacked and destroyed, and Ravel begins a terrifying odyssey through time.For the attackers were another time-tampering team from still a different future era. And Ravel himself is not only in growing danger but the human world as we know it…